Iridium etchant methods for anisotropic profile

ABSTRACT

A method of etching an electrode layer (e.g., a platinum electrode layer or an iridium electrode layer) disposed on a substrate to produce a semiconductor device including a plurality of electrodes separated by a distance equal to or less than about 0.3 μm and having a profile equal to or greater than about 85°. The method comprises heating the substrate to a temperature greater than about 150° C., and etching the electrode layer by employing a high density inductively coupled plasma of an etchant gas comprising oxygen and/or chlorine, argon and a gas selected from the group consisting of BCl 3 , HBr, HCl and mixtures thereof. A semiconductor device having a substrate and a plurality of electrodes supported by the substrate. The electrodes have a dimension (e.g., a width) which include a value equal to or less than about 0.3 μm and a profile equal to or greater than about 85°.

This is a continuation-in-part patent application of the copendingpatent application entitled “Etching Methods for Anisotropic PlatinumProfile,” Ser. No. 09/006,092, filed Jan. 13, 1998.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to plasma etching of platinum and iridium. Morespecifically, this invention provides a method for plasma etching ofplatinum and iridium for producing semiconductor integrated circuitscontaining platinum and iridium electrodes.

2. Description of the Prior Art

The implementation of digital information storage and retrieval is acommon application of modern digital electronics. Memory size and accesstime serve as a measure of progress in computer technology. Quite oftenstorage capacitors are employed as memory array elements. As the stateof the art has advanced, small-feature-size high density dynamic randomaccess memory (DRAM) devices require storage capacitors of largercapacitance having high dielectric constant materials. The highdielectric constant materials or ferroelectric materials are madeprimarily of sintered metal oxide and contain a substantial amount ofvery reactive oxygen. In the formation of capacitors with suchferroelectric materials or films, the electrodes must be composed ofmaterials with least reactivity to prevent oxidation of the electrodeswhich would decrease the capacitance of storage capacitors. Therefore,precious metals, such as platinum (Pt), palladium (Pd), iridium (Ir),etc., are preferred metals used in the manufacture of capacitors forhigh density DRAM.

Among the possible precious metals for capacitor electrodes, platinumand iridium have emerged as an attractive candidates because they areinert to oxidation and are known to have a leakage current (<10⁻⁹amps/cm²) lower than other electrodes such as RuO₂ and Pd. Platinum andiridium also are good conductors.

In the prior art, platinum and iridium etching have been conducted bymeans of isotropic etching, such as wet etching with aqua regia, or byanisotropic etching, such as ion milling with Ar gas or by other means.Because of the nature of isotropic etching, using wet etching with aquaregia causes deteriorated processing accuracy. The grade of precision inisotropic etching is not high enough for fine pattern processing.Therefore, it is difficult to perform submicron patterning of platinumand iridium electrodes due to their isotropic property. Furthermore, aproblem with ion milling (i.e. anisotropic etching) occurs because theetching speed on platinum and iridium, which is to form the electrode,is too slow for mass production.

In order to increase processing accuracy in etching platinum andiridium, research and development has been quite active, particularly inthe area of etching platinum and iridium by means of a dry etchingprocess where etchant gases (e.g., Cl₂, HBr, O₂, etc.) are used. Thefollowing prior art is representative of the state of art with respectto etching platinum with a plasma of etching gases.

U.S. Pat. No. 5,492,855 to Matsumoto et al. discloses a semiconductordevice manufacturing method, wherein an insulation layer, a bottomelectrode Pt layer, a dielectric film and a top electrode Pt layer areprovided on top of a substrate having already-completed circuit elementsand wiring, and then, a capacitor is formed by selectively dry etchingthe bottom electrode Pt layer after selectively dry etching the topelectrode Pt layer and the dielectric film. The manufacturing methoduses a gas containing an S component as etching gas for Pt etching, oran etching gas containing S component as an additive gas; and also itimplants S into the Pt layer before the Pt dry etching process by meansof ion implantation to compose a S and Pt compound, and then dry etchesthe Pt compound thus composed.

U.S. Pat. No. 5,527,729 to Matsumoto et al. discloses process steps toform on a substrate in which circuit elements and wirings, etc., arealready shaped, an insulation layer, a first metal layer, a dielectricfilm and a second metal layer. A top electrode and a capacitance filmare formed by dry etching the second metal layer and the dielectricfilm. A bottom electrode is formed by dry etching the first metal layer.The etching gas for dry etching the second metal layer is a mixed gascontaining hydrogen halide (e.g. HBr) and oxygen, having a ratio ofoxygen against the total of hydrogen halide and oxygen set at about10%-35%. The etching gas is also taught as a gas containing hydrocarbon,such as chloroform. Matsumoto et al. employs a silicon oxide layer asthe insulation layer on the substrate, and a platinum layer or palladiumlayer as the first and second metal layers. Dry etching of the secondmetal layer and dielectric film is conducted in a low pressure regionnot higher than about 5 Pa, where the etching speed is high. Matsumotoet al. further teaches that where a mixed gas of hydrogen halide andoxygen is used as the etching gas, the etching speed on the siliconoxide layer can be made sufficiently low relative to that on the secondmetal layer made of a platinum layer or a palladium layer; in this way,the excessive etching of the silicon oxide layer underlying the firstmetal layer is avoided, and damage to the circuit elements and wiring,etc. underneath the silicon oxide layer can be prevented. Furthermoreaccording to Matsumoto et al, the ratio of etching speed of the platinumand dielectric material to the resist can be increased by lowering theetching speed on the resist. Therefore, etching of the platinum anddielectric material may be conducted by using a mask of normallay-thickness resist (generally speaking, about 1.2 μm to about 2.0 μmthick), instead of using a conventional thick-layer resist (about 3 μmand thicker).

Chou et al. in an article entitled “Platinum Metal Etching in aMicrowave Oxygen Plasma”, J. Appl. Phys. 68 (5), Sep. 1, 1990, pages2415-2423, discloses a study to understand the etching of metals in bothplasma and chemical systems. The study found that the etching ofplatinum foils in an oxygen plasma generated in a flow-type microwavesystem and that very rapid etching (˜6 Å/s) took place even at low powerinputs (200 W). The principal plasma parameters, including oxygen atomconcentration, ion concentration, and electron temperature, weremeasured by Chou et al. as a function of distance below the microwavecoupler. These were correlated to the rate of foil etching, whichdecreased with increasing distance from the coupler. On the basis ofthese correlations Chou et al. formulated a simple mechanistic model.The study by Chou et al. further found that the etching of platinum inan oxygen plasma jet results from the concomitant action of oxygen atomsand high energy electrons.

Nishikawa et al. in an article entitled “Platinum Etching and PlasmaCharacteristics in RF Magnetron and Electron Cyclotron ResonancePlasmas”, Jpn. J. Appl. Phys., Vol. 34 (1995), pages 767-770, disclosesa study wherein the properties of platinum etching were investigatedusing both rf magnetron and electron cyclotron resonance (ECR) plasmas,together with measurement of the plasma parameters (neutralconcentration, plasma density, etc.). Nishikawa et al. performedexperiments in Cl₂ plasmas over a pressure ranging from 0.4 to 50 mTorr.In rf magnetron plasmas, the etch rate of Pt was constant at thesubstrate temperature of from 20 to 160° C. The etch rate and the plasmaelectron density increased with gas pressure decreasing from 50 to 5mTorr. In ECR plasmas for rf power of 300 W, Nishikawa et al. found thatthe etch rate of Pt was almost constant (˜100 nm/min) with gas pressuredecreasing from 5 to 0.4 mTorr, while the plasma electron densitygradually increased with decreasing gas pressure. The study by Nishikawaet al. discusses these experimental results with respect to therelationship between the etch yield and the ratio of neutral Cl₂ fluxand ion flux incident on the substrate.

Yokoyama et al. in an article entitled “High-Temperature Etching ofPZT/Pt/TiN Structure by High-Density ECR Plasma”, Jpn. J. Appl. Phys.,Vol. 34 (1995), pages 767-770, discloses a study wherein micronpatterning technologies for the PZT/Pt/TiN/Ti structure with a spin onglass (SOG) mask are demonstrated using a high-density electroncyclotron resonance (ECR) plasma and a high substrate temperature above300° C. A 30%-Cl₂/Ar gas was used to etch a lead zirconate titanate(PZT) film. No deposits remained, which resulted in an etched profile ofmore than 80°. A 40%-O₂/Cl₂ gas was used to etch a Pt film. The etchingwas completely stopped at the Ti layer. 30-nm-thick deposits remained onthe sidewall. They were removed by Yokoyama et al. after dipping inhydrochloric acid. The etched profile of a Pt film was more than 80°.The Ti/TiN/Ti layer was etched with pure Cl₂ gas. The size shift fromthe SOG mask was less than 0.1 μm. Yokoyama et al. did not detect anyinterdiffusion between SOG and PZT by transmission electron microscopyand energy dispersive x-ray spectroscopy (TEM-EDX) analysis.

Yoo et al. in an article entitled “Control of Etch Slope During Etchingof Pt in Ar/Cl₂/O₂ Plasmas”, Jpn. J. Appl. Phys., Vol. 35 (1996), pages2501-2504, teaches etching of Pt patterns of the 0.25 μm design rule at20° C. using a magnetically enhanced reactive ion etcher (MERIE). Yoo etal. found that a major problem of etching with a MERIE was theredeposition of the etch products onto the pattern sidewall, making itdifficult to reduce the pattern size. In both cases separately using aphotoresist mask and an oxide mask, the redeposits of the etch productsonto the sidewall were reduced by the addition of Cl₂ to Ar, althoughthe etched slope was lowered to 45°. The redeposits were removed by anHCl cleaning process.

Kotecki in an article entitled “High-K Dielectric Materials for DRAMCapacitors”, Semiconductor International, November 1996, pages 109-116,the potential advantages of incorporating high-dielectric materials intoa storage capacitor of a dynamic random access memory (DRAM) aredescribed and the requirements of the high dielectric layer are reviewedas they relate to use in a simple stack capacitor structure suitable forthe gigabit generation. Kotecki teaches that when considering the use ofhigh-dielectric materials in a stack capacitor structure, the followingissues need to be addressed: electrode patterning, high-dielectricmaterial/barrier interaction, electrode/high-dielectric materialinteraction, surface roughness (e.g. hilocking, etc.), step coverage,high-dielectric material uniformity (e.g. thickness, composition, grainsize/orientation, etc.), and barrier (e.g. O₂ and Si diffusion,conductivity, contact resistance and interactions, etc.). Variousmaterials and combinations of materials were studied by Kotecki for usewith perovskite dielectrics including the noble metals (i.e. Pt, Ir, Pd)and conductive metal oxides (i.e. IrO₂ and RuO₂). The work function ofthese materials, their ability to be patterned by dry etching, thestability of the surface with regards to surface roughening and theirsuitability in a semiconductor fabricator are listed by Kotecki in thefollowing Table I:

TABLE I Comparison of the Properties of Various Electrode MaterialsSuitable for Use with Perovskite Dielectrics Material Work Dry SurfaceDeposition Selection Function Etch Stability Method Pt 5.6-5.7 difficultpotential sputtering problem Ru 4.7 easy/dangerous potential sputteringproblem RuO₂/Ru easy/dangerous good reactive sput- tering Ir 5.0-5.8difficult good sputtering IrO₂/Ir difficult good reactive sput- teringPd 5.1-5.6 difficult ? sputtering

Kotecki further teaches in the article entitled “High-K DielectricMaterials for DRAM Capacitors” that one of the major problems whichneeds to be overcome with respect to the manufacturing of DRAM chipsusing capacitors is the problem of electrode patterning. There areminimal volatile species produced during the dry etching of the noblemetal electrodes such as Pt, Ru, Pd and Ir. Since the etch mechanism isprimarily by physical sputtering, even during a RIE process, fences aretypically formed on the sides of the photoresist. To eliminate theproblem of fencing, it is possible to etch the fence layer and erode thesides of the photoresist during the etch process which leads to “clean”metal structures but with sloping sidewall angles and a loss of controlover critical feature sizes. As the dimension of the feature shrinks to0.18 μm or below, only limited tapering of the sidewall angle can betolerated. Kotecki presents in the following Table II some of thehigh-dielectric materials which have been considered for use in a DRAMcapacitor, the various methods which can be used to form the films, andthe range of reported permittivites:

TABLE II A Comparison of Various High-Dielectric Materials and Methodfor Formation and Dielectric Constants Material Deposition Methods∈_(T)(thin films) SrTiO₃ MOCVD, ECR-CVD, sol-gel,  90-240 sputtering,PLD (Ba, Sr)TiO₃ MOCVD, ECR-CVD, sol-gel, 160-600 sputtering, PLD PLTMOCVD, sol-gel, sputtering, PLD 400-900 PZT and PLZT MOCVD, sol-gel,sputtering, PLD >1000

Milkove et al. reported in a paper entitled “New Insight into theReactive Ion Etching of Fence-Free Patterned Platinum Structures” at the43rd Symposium of AVS, October 1996, Philadelphia, Pa., that aninvestigation was undertaken to characterize the time progression of thePt etch process during the reactive ion etching (RIE) of fence-freepatterned structures. The experiment by Milkove et al. consisted ofcoprocessing two oxidized Si wafers possessing identical 2500 Å thick Ptfilm layers, but different photoresist (PR) mask thicknesses. Etchingwas suspended at 20, 40, 60 and 80% of the full etch process in order tocleave off small pieces of wafer for analysis by a scanning electronmicroscopy (SEM). Using Cl₂-based RIE conditions known to producefence-free etching for 2500 Å thick film layers, Milkove et al.discovered that a severe fence actually coats the PR mask during thefirst 20% of the etch process. As the etch continues the fence structureevolves, achieving a maximum height and width followed by progressiverecession until disappearing completely prior to process endpoint. Thedata from Milkove et al. shows that the final profile of an etched Ptstructure possess a functional dependence on the initial thickness andslope of the PR mask, as well as on the initial thickness of the Ptlayer. Milkove et al. further reported in the paper entitled “NewInsight Into The Reactive Ion Etching of Fence-free Patterned PlatinumStructures” that the observed behavior of the transient fence providesthe strongest evidence to date supporting the existence of a chemicallyassisted physical sputtering component associated with the RIE of Ptfilms in halogen-based plasmas.

Keil et al. teaches in an article entitled “The Etching of PlatinumElectrodes for PZT Based Ferroelectric Devices”, Electrochemical SocietyProceedings, Vol. 96-12 (1996), pages 515-520, that the technicaldifficulties of fabricating capacitors employing platinum Pt etching ismost often dominated by sputtering processes. While oxygen and/orvarious gaseous chlorides or fluorides are used to chemically enhancethe etch process, the products of both etch mechanisms are usually oflow volatility and tend to redeposit on the wafer. After etching, largewall-like structures extend up from the edges of the Pt region. Thesewall-like structures are frequently referred to as “veils” or “fences”or “rabbit ears” and can reach lengths which are more than double thethickness of the Pt film to which they are attached. The existence ofsuch structures makes useful deposition of the PZT layer impossible.Keil et al. further teaches that even when one is able to attenuateredeposition to the point where only small “nub” like features arepresent, the high electric fields which will form at such “nubs”enhances the likelihood for dielectric breakdown. Although processconditions can be found which result in either low redeposition or evenno redeposition, they most often also give an unacceptably taperedplatinum profile angle. Keil et al. observed that redeposition becomesmore severe as process conditions are pushed toward those which giveincreasingly vertical sidewalls. While a post etch wet clean in asolvent bath is frequently used, the heavy redeposition which attendsthe pursuit of vertical sidewalls regularly renders this approachminimally effective.

The foregoing prior art illustrates that generally a clean verticaldense area profile and CD (critical dimension) control of the etchprofiles are critical factors for successful plasma etching of 1-Gbit(and beyond) DRAM ferroelectric devices possessing platinum electrodes.Redeposition and profile control are found to be strongly interlinked.Optimization of both profile angle and redeposition requires a tradeoffbetween the two. Where as vigorous post etch cleaning (e.g. wet cleaningwith acid, mechanical polishing, etc.) can relieve some of the need toachieve a deposition free plasma etch, such post etch cleaning does notpossess the accuracy that is desired as the platinum electrode itself istypically eroded and/or deteriorated by currently known post etchcleaning methods. The same would be true for an iridium electrode.

Therefore, what is needed and what has been invented is a method foretching a platinum layer and an iridium layer to produce a high densityintegrated circuit semiconductor device having platinum electrodes oriridium electrodes with a high degree (i.e., ≧85°) of platinum oriridium profile anisotropy. What is further needed and what has beeninvented is a semiconductor device including a plurality of platinum oriridium electrodes respectively having a platinum or iridium profileequal to or greater than about 85° and separated by a distance equal toor less than about 0.3 μm with each electrode having a criticaldimension (e.g., a width) equal to or less than about 0.3 μm.

SUMMARY OF THE INVENTION

The present invention broadly provides a method of etching a platinumlayer disposed on a substrate comprising the steps of:

a) providing a substrate supporting a platinum layer;

b) heating the substrate (such as with a pedestal supporting thesubstrate) of step (a) to a temperature greater than about 150° C.; and

c) etching the platinum layer including employing a high density plasmaof an etchant gas comprising a halogen containing gas (e.g., a halogensuch as chlorine) and a noble gas (e.g., argon) to produce the substratesupporting at least one etched platinum layer.

In another embodiment of the present invention, the present inventionbroadly provides:

a) providing a substrate supporting a iridium layer;

b) heating the substrate of step (a) to a temperature greater than about150° C.; and

c) etching the iridium layer including employing a high density plasmaof an etchant gas comprising a halogen-containing gas, and a noble gasto produce said substrate supporting at least one etched iridium layer.The etchant gas may additionally include a gas selected from the groupconsistng of O₂ and BCl₃. Alternatively, the etchant gas mayadditionally include a gas selected from the group consisting of O₂,HCl, HBr, and mixtures thereof. The substrate of step (a) may be heatedby heating the pedestal supporting the substrate to a sufficienttemperature to cause the substrate to possess a temperature greater thanabout 150° C.

In the foregoing methods, the platinum layer and the iridium layer arepreferably a platinum electrode layer and an iridium electrode layer,respectively. The high density plasma of an etchant gas is a plasma ofan etchant gas having an ion density greater than about 10⁹/cm³,preferably greater than about 10¹¹/cm³. The etchant gas may also includea gas selected from the group consisting of BCl₃, HBr, and mixturesthereof. The platinum layer and the iridium layer may each additionallycomprise a mask layer disposed on a selected part of the particularrespective layer to selectively protect the particular respective layerduring the etching step. In the embodiment of the present invention foretching iridium, if the mask layer is a hard mask layer comprising Tiand/or TiN, the etchant gas having Ar/Cl₂/O₂ chemistry with high O₂concentration produces an iridium to Ti and/or TiN selectivity ofgreater than about 8 (preferably greater than about 10) during etchingof iridium. The platinum layer and the iridium layer may each alsoadditionally comprise a protective layer disposed on the selected partof the particular respective layer between the mask layer and theparticular respective layer. The mask layer may be removed during orafter the etching step. Similarly, the protective layer may be removedduring or after the etching step.

The platinum layer is part of or is contained in a platinum wafer, andthe method of etching a platinum layer additionally comprises disposingthe platinum wafer including the platinum layer in a high density plasmachamber having a coil inductor and a wafer pedestal; and performing theetching step (c) in the high density plasma chamber under the followingprocess conditions:

Process Parameters Etchant Gas Flow 50 to 500 sccm Halogen Gas (e.g.,Cl₂) 20% to 95% by vol. Noble Gas (e.g., Ar) 5% to 80% by vol. Pressure,mTorr 0.1 to 300 milliTorr RF Power (watts) 100 to 5000 watts of CoilInductor RF Power (watts) 50 to 3000 watts of Wafer Pedestal Temperature(° C.) of 150° to 500° C. Platinum Wafer Platinum Etch Rate (Å/min) 200to 6000 Å/min RF Frequency of 100 K to 300 MHz Coil Inductor RFFrequency of 100 K to 300 MHz Wafer Pedestal

The etched platinum layer includes a platinum profile equal to orgreater than about 85°, more preferably equal to or greater than about87°, most preferably equal to or greater than about 88.5°. The etchantgas for the process conditions immediately above may alternativelycomprise from about 10% to about 90% by vol. of a halogen (e.g., Cl₂),from about 5% to about 80% by vol. of a noble gas (e.g., argon), andfrom about 4% to about 25% by vol. HBr and/or BCl₃.

The iridium layer is part of or is contained in an iridium wafer, andthe method of etching an iridium layer additionally comprises disposingthe iridium wafer including the iridium layer in a high density plasmachamber having a coil inductor and a wafer pedestal; and performing theetching step (c) in the high density plasma chamber under the followingprocess conditions:

Process Parameters Etchant Gas Flow 50 to 500 sccm Halogen Gas (e.g.,Cl₂) 10% to 60% by vol. Noble Gas (e.g., Ar) 30% to about 80% by vol.Oxygen 5% to 40% by vol. Pressure, mTorr 0.1 to 300 milliTorr RF Power(watts) 100 to 5000 watts of Coil Inductor RF Power (watts) 50 to 3000watts of Wafer Pedestal Iridium Etch Rate (Å/min) 200 to 6000 Å/min RFFrequency of 100 K to 300 MHz Coil Inductor RF Frequency of 100 K to 300MHz Wafer Pedestal

The etched iridium layer includes an iridium profile equal to or greaterthan about 80°, more preferably equal to or greater than about 82°, mostpreferably equal to or greater than about 85.0°. The etchant gas for theprocess conditions immediately above may alternatively comprise fromabout 5% to about 20% by vol. oxygen, from about 10% to about 60% byvol. of a halogen (e.g., Cl₂), from about 30% to about 80% by vol. of anoble gas (e.g., argon), and from about 5% to about 20% by vol. HBrand/or HCl.

The present invention also broadly provides a method for producing acapacitance structure including an electrode (i.e., a platinum oriridium electrode) comprising the steps of:

a) providing a substrate supporting a layer (i.e., a platinum electrodelayer or an iridium electrode layer) and at least one mask layerdisposed on a selected part of the layer;

b) heating the substrate of step (a) to a temperature greater than about150° C.; and

c) etching the layer including employing a plasma of an etchant gascomprising a halogen (e.g., chlorine) and a noble gas (e.g., argon) toproduce a capacitance structure having at least one electrode (i.e.,platinum electrode or iridium electrode).

The at least one mask layer is removed during or after the etching step(c) immediately above. The layer of step (a) immediately above mayadditionally comprise a protective layer disposed on the selected partof the layer between the mask layer and the layer. The etched layer(i.e. the etched platinum layer or the etched iridium layer) produced bythe etching step (c) immediately above includes a profile (i.e. aplatinum profile or an iridium profile) equal to or greater than about80° iridium and equal to or greater than about 85° for platinum, morepreferably equal to or greater than about 87°, most preferably equal toor greater than about 88.5°.

In a preferred embodiment of the invention for etching platinum, theetchant gas of the plasma of step (c) more specifically includes ahalogen (e.g., chlorine), a noble gas (e.g., argon), and a gas selectedfrom the group consisting of HBr, BCl₃ and mixtures thereof. Theplatinum electrode layer is part of or is contained in a platinumelectrode wafer, and the method for producing a capacitance structureincluding a platinum electrode layer additionally comprises disposing,prior to the etching step (c), the platinum electrode wafer in a highdensity plasma chamber having a coil inductor and a wafer pedestal; andperforming the etching step (c) in the high density plasma chamber underthe following previously indicated process conditions:

Process Parameters Etchant Gas Flow 50 to 500 sccm Halogen Gas (e.g.,Cl₂) about 10% to about 90% by vol. Noble Gas (e.g., Ar) about 5% toabout 80% by vol. HBr and/or BCl₃ about 4% to about 25% by vol.Pressure, mTorr 0.1 to 300 milliTorr RF Power (watts) 100 to 5000 wattsof Coil Inductor RF Power (watts) 50 to 3000 watts of Wafer PedestalTemperature (° C.) of about 150° to about 500° C. Platinum ElectrodeWafer Platinum Etch Rate (Å/min) 200 to 6000 Å/min RF Frequency of 100 Kto 300 MHz Coil Inductor RF Frequency of 100 K to 300 MHZ Wafer Pedestal

The produced platinum electrodes are separated by a distance or spacehaving a dimension equal to or less than about 0.3 μm. Each of theplatinum electrodes include a dimension having a value equal to or lessthan about 0.6 μm, preferably equal to or less than about 0.3 μm. Morepreferably, each of the platinum electrodes have a width equal to orless than about 0.3 μm, a length equal to or less than about 0.6 μm, anda height equal to or less than about 0.6 μm. The plasma of the etchantgas for etching platinum comprises a high density inductively coupledplasma. The etchant gas preferably comprises a noble gas selected fromthe group consisting of helium, neon, argon, krypton, xenon, radon, andmixtures thereof. More preferably, the noble gas is selected from thegroup consisting of helium, neon, argon, and mixtures thereof. Mostpreferably, the noble gas is argon. As was previously indicated, theetchant gas of the high density inductively coupled plasma for etchingplatinum most preferably comprises, or preferably consists of orconsists essentially of, chlorine, argon, and HCl and/or HBr.

In a preferred embodiment of the invention for etching iridium, theetchant gas of the plasma of step (c) more specifically includes oxygen,a halogen (e.g., chlorine), a noble gas (e.g., argon), and a gasselected from the group consisting of HBr, HCl and mixtures thereof. Theiridium electrode layer is part of or is contained in an iridiumelectrode wafer, and the method for producing a capacitance structureincluding an iridium electrode layer additionally comprises disposing,prior to the etching step (c), the iridium electrode wafer in a highdensity plasma chamber having a coil inductor and a wafer pedestal; andperforming the etching step (c) in the high density plasma chamber underthe following previously indicated process conditions:

Process Parameters Etchant Gas Flow 50 to 500 sccm Oxygen about 5% toabout 20% by vol. Halogen Gas (e.g., Cl₂) about 10% to about 60% by vol.Noble Gas (e.g., Ar) about 30% to about 80% by vol. HBr and/or HCl about5% to about 20% by vol. Pressure, mTorr 0.1 to 300 milliTorr RF Power(watts) 100 to 5000 watts of Coil Inductor RF Power (watts) 50 to 3000watts of Wafer Pedestal Temperature (° C.) of about 150° to about 500°C. Iridium Electrode Wafer Iridium Etch Rate (Å/min) 200 to 6000 Å/minRF Frequency of 100 K to 300 MHz Coil Inductor RF Frequency of 100 K to300 MHz Wafer Pedestal

The plasma of the etchant gas for etching iridium comprises a highdensity inductively coupled plasma. The etchant gas preferably comprisesa noble gas selected from the group consisting of helium, neon, argon,krypton, xenon, radon, and mixtures thereof. More preferably, the noblegas is selected from the group consisting of helium, neon, argon, andmixtures thereof. Most preferably, the noble gas is argon. As waspreviously indicated, the etchant gas of the high density inductivelycoupled plasma for etching iridium most preferably comprises, orpreferably consists of or consists essentially of, chlorine, argon, andoxygen or BCl₃; alternatively, oxygen, chlorine, argon, and HCl and/orHBr.

The present invention further broadly provides a method of manufacturinga semiconductor device comprising the steps of:

a) forming a patterned resist layer, a mask layer and an electrode layer(i.e. a platinum electrode layer or an iridium electrode layer) on asubstrate having circuit elements formed thereon;

b) etching a portion of the mask layer including employing a plasma ofan etchant gas to break through and to remove the portion of the masklayer from the electrode layer to produce the substrate supporting thepatterned resist layer, a residual mask layer, and the electrode layer;

c) removing the resist layer of step (b) to produce the substratesupporting the residual mask layer and the electrode layer;

d) heating the substrate of step (c) to a temperature greater than about150° C.; and

e) etching the electrode layer of step (d) including employing a highdensity plasma of an etchant gas. In the embodiment of the invention foretching a platinum layer, the etchant gas preferably comprises a halogengas (e.g., chlorine) and a noble gas (e.g., argon) to produce asemiconductor device having at least one platinum electrode. In theembodiment of the invention for etching an iridium layer, the etchantgas comprises oxygen, a halogen gas (e.g. chlorine) and a noble gas(e.g. argon) to produce a semiconductor device having at least oneiridium electrode.

The present invention also further broadly provides a method of etchingan electrode layer disposed on a substrate comprising the steps of:

a) providing a substrate supporting an electrode layer (i.e. a platinumelectrode layer or an iridium electrode layer), a protective layer onthe electrode layer, and a mask layer on the protective layer, and apatterned resist layer on the mask layer;

b) etching a portion of the mask layer including employing a plasma ofan etchant gas to break through and to remove the portion of the masklayer from the protective layer to expose part of the protective layerand to produce the substrate supporting the electrode layer, theprotective layer on the electrode layer, a residual mask layer on theelectrode layer, and the patterned resist layer on the residual masklayer;

c) removing the patterned resist layer from the residual mask layer ofstep (b) to produce the substrate supporting the electrode layer, theprotective layer on the electrode layer, and the residual mask layer onthe protective layer;

d) heating the substrate of step (c) to a temperature greater than about150° C.;

e) etching the exposed part of the protective layer to expose part ofthe electrode layer and to produce the substrate supporting theelectrode layer, a residual protective layer on the electrode layer, andthe residual mask layer on the residual protective layer; and

f) etching the exposed part of the electrode layer of step (e) includingemploying a high density plasma of an etchant gas. If the electrodelayer being etched comprises platinum, the etchant gas comprises ahalogen gas (e.g., chlorine) and a noble gas (e.g., argon) to producethe substrate supporting an etched platinum electrode layer having theresidual protective layer on the etched platinum electrode layer, andthe residual mask layer on the residual protective layer. If theelectrode layer being etched includes iridium, the etchant gas comprisesoxygen, a halogen gas (e.g. chlorine) and a noble gas (e.g. argon) toproduce the substrate supporting an etched iridium electrode layerhaving the residual protective layer on the etched iridium electrodelayer, and the residual mask layer on the residual protective layer.

The patterned resist layer is preferably removed from the residual masklayer before heating the substrate to a temperature greater than about150° C. because such high temperatures would destroy the resist layer.The residual mask layer may be removed from the electrode layer eitherbefore or after heating of the substrate to a temperature greater thanabout 150° C., and during or after the etching step. The electrode layer(i.e. a platinum electrode layer or an iridium electrode layer) is partof or is contained in a wafer (i.e. a platinum electrode wafer or aniridium electrode wafer). The purpose of the protective layer is toensure the adhesion between the mask layer and the platinum and iridiumlayers and also to respectively maintain the platinum profile and theiridium profile of the platinum electrode layer and the iridiumelectrode layer, respectively, especially during the etching process ofthe present invention. Preferably, the residual protective layers arerespectively removed from the etched platinum and iridium electrodesafter the platinum and iridium etching step.

As previously indicated, etching of the platinum electrode layer toproduce the platinum electrodes of the present invention is performed ina high density plasma chamber. The platinum etching step employs a highdensity plasma of an etchant gas preferably consisting of, or consistingessentially of, a halogen gas (e.g., chlorine), a noble gas (i.e.,argon) and HBr and/or BCl₃. The high density plasma chamber possesses aseparate control for ion flux and a separate control for ion energy. Aspreviously indicated, the ion density of the high density plasma in thehigh density plasma chamber is greater than about 10⁹/cm³.

The high density plasma chamber for the method of manufacturing asemiconductor device and for the method of etching a platinum electrodelayer disposed on a substrate includes a coil inductor and a waferpedestal; and the platinum etching step in both of the methods isperformed in the high density plasma chamber under the followingpreviously mentioned process conditions:

Process Parameters Etchant Gas Flow 50 to 500 sccm Halogen Gas (e.g.,Cl₂) about 10% to about 90% by vol. Noble Gas (e.g., argon) about 5% toabout 80% by vol. HBr and/or BCl₃ about 4% to about 25% by vol.Pressure, mTorr 0.1 to 300 milliTorr RF Power (watts) 100 to 5000 wattsof Coil Inductor RF Power (watts) 50 to 3000 watts of Wafer PedestalTemperature (° C.) of about 150° to about 500° C. Platinum ElectrodeWafer Platinum Etch Rate (Å/min) 200 to 6000 Å/min RF Frequency of 100 Kto 300 MHz Coil Inductor RF Frequency of 100 K to 300 MHz Wafer Pedestal

As further previously indicated, etching of the iridium electrode layerto produce the iridium electrodes of the present invention is performedin a high density plasma chamber. The iridium etching step employs ahigh density plasma or a low density plasma of an etchant gas preferablyconsisting of, or consisting essentially of, or consisting essentiallyof, a halogen gas (e.g., chlorine) and a noble gas (i.e., argon), morepreferably a halogen gas (e.g., chlorine), a noble gas (i.e., argon) andoxygen or BCl₃, or oxygen (O₂), a halogen gas (e.g. Cl₂), a noble gas(e.g Ar), and HCl and/or HBr. The high density plasma chamber possessessa separate control for ion flux and a separate control for ion energy.As previously indicated, the ion density of the high density plasma inthe high density plasma chamber is greater than about 10⁹/cm³.

The high density plasma chamber for the method of manufacturing asemiconductor device and for the method of etching iridium electrodelayer disposed on a substrate includes a coil inuctor and a waferpedestal; and the iridium etching step in both of the methods isperformed in high density plasma chamber under the following previouslymentioned process conditions:

Process Parameters Etchant Gas Flow 50 to 500 Oxygen 5% to 20% by volumeHalogen Gas (e.g., Cl₂) about 10% to about 60% by vol. Noble Gas (e.g.,argon) about 30% to about 80% by vol. HBr and/or HCl about 5% to about20% by vol. Pressure, mTorr 0.1 to 300 milliTorr RF Power (watts) 100 to5000 watts of Coil Inductor RF Power (watts) 50 to 3000 watts of WaferPedestal Temperature (° C.) of about 150° to about 500° C. IridiumElectrode Wafer Iridium Etch Rate (Å/min) 200 to 6000 Å/min RF Frequencyof 100 K to 300 MHz Coil Inductor RF Frequency of 100 K to 300 MHz WaferPedestal

The present invention yet also further broadly provides a semiconductordevice, more specifically a capacitance structure, comprising asubstrate, and at least two electrodes (i.e., platinum electrodes oriridium electrodes) supported by the substrate. The electrodes have aprofile equal to or greater than about 85°, preferably equal to orgreater than about 87°, more preferably equal to or greater than about88.5°. The electrodes are separated by a distance or space having adimension equal to or less than about 0.3 μm. Each of the electrodesinclude a dimension having a value equal to or less than about 0.6 μm,preferably equal to or less than about 0.3 μm. More preferably, each ofthe electrodes have a width equal to or less than about 0.3 μm, a lengthequal to or less than about 0.6 μm, and a height equal to or less thanabout 0.6 μm.

The foregoing provisions along with the various ancillary provisions andfeatures which will become apparent to those skilled in the art as thefollowing description proceeds, are attained by the practice of thepresent invention, a preferred embodiment thereof shown with referenceto the accompanying drawings, by way of example only, wherein:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view of a semiconductor wafer having asemiconductor substrate, a barrier layer disposed on the semiconductorsubstrate, an electrode layer (i.e., a platinum electrode layer or aniridium electrode layer) disposed on the barrier layer, a mask layerdisposed on the electrode layer, and a patterned resist disposed on themask layer;

FIG. 2 is a side elevational view of the semiconductor wafer of FIG. 1additionally including a protective layer disposed on the electrodelayer (i.e., a platinum electrode layer or an iridium electrode layer)between the mask layer and the electrode layer;

FIG. 3 is a vertical sectional view of a prior art plasma processingapparatus including a plasma etching reactor with an electromagneticunit for enhancing a plasma;

FIG. 4 is a diagram of a flux produced by a magnetic field andillustrated as rotating around a center axis;

FIG. 5 is a side elevational view of the semiconductor wafer of FIG. 1after etching and removing a portion of the mask layer from the surfaceof the electrode layer (i.e., a platinum electrode layer or an iridiumelectrode layer) to expose the electrode layer;

FIG. 6 is a side elevational view of the semiconductor wafer of FIG. 2after etching and removing a portion of the mask layer from the surfaceof the protective layer to expose the protective layer;

FIG. 7 is a side elevational view of the semiconductor wafer of FIG. 5after the patterned resist layer has been removed from a portion of themask layer with the removed patterned resist layer being represented asbroken lines;

FIG. 8 is a side elevational view of the semiconductor wafer of FIG. 6after etching and removing a portion of the protective layer off of thesurface of the layer (i.e., a platinum electrode layer or an iridiumelectrode layer), and after removing the patterned resist layer from aportion of the mask layer with the removed patterned resist layer beingrepresented as broken lines;

FIG. 9 is a side elevational view of the semiconductor wafer of FIG. 7after the electrode layer (i.e., the platinum electrode layer or theiridium electrode layer) has been etched to produce an etched electrodelayer;

FIG. 10 is a side elevational view of the semiconductor wafer of FIG. 8after the electrode layer (i.e., the platinum electrode layer or theiridium electrode layer) has been etched to produce an etched electrodelayer;

FIG. 11 is a side elevational view of the semiconductor wafer of FIG. 7after the electrode layer (i.e., the platinum electrode layer or theiridium electrode layer) has been etched to produce an etched electrodelayer with a residual mask layer on top thereof;

FIG. 12 is a side elevational view of the semiconductor wafer of FIG. 8after the electrode layer (i.e., the platinum electrode layer or theiridium electrode layer) has been etched to produce an etched electrodelayer with a residual mask layer on top of the residual protectivelayer;

FIG. 13 is a side elevational view of the semiconductor wafer of FIG. 11with the residual mask layer removed from the surface of the etchedelectrode layer;

FIG. 14 is a side elevational view of the semiconductor wafer of FIG. 12with the residual mask layer and the residual protective layer removedfrom the surface of the etched electrode layer (i.e., the etchedplatinum electrode layer or the iridium etched electrode layer);

FIG. 15 is a side elevational view of semiconductor wafer of FIG. 11after the residual mask layer has been removed from the surface of theetched electrode layer (i.e., the etched platinum electrode layer or theetched iridium electrode layer) and with the barrier layer having beenetched;

FIG. 16 is a side elevational view of semiconductor wafer of FIG. 12after the residual mask layer and the residual protective layer havebeen removed from the surface of the etched electrode layer (i.e., theetched platinum electrode layer or the etched iridium electrode layer)and with the barrier layer having been etched;

FIG. 17 is a simplified cut-away view of an inductively coupled RFplasma reactor which may be employed in etching the electrode layer(i.e., the platinum electrode layer or the iridium electrode layer) toproduce a semiconductor device;

FIG. 18 is a simplified cut-away view of another inductively coupled RFplasma reactor which may be employed in etching the electrode layer(i.e., the platinum electrode layer or the iridium electrode layer) toproduce a semiconductor device;

FIG. 19 is a picture showing an elevational view of a test semiconductorwafer for Example I after a platinum electrode layer was etched inaccordance with the process conditions listed in Example I;

FIG. 20 is a picture showing an elevational view of the testsemiconductor wafer of FIG. 19 after the oxide mask was removed;

FIG. 21 is a drawing representing the elevational view in the picture ofFIG. 19 with the respective parts identified by a reference numeral;

FIG. 22 is a drawing representing the elevational view in the picture ofFIG. 20 with the respective parts identified by a reference numeral;

FIG. 23 is a picture showing an elevational view of a test semiconductorwafer for Example II after a platinum electrode layer was etched inaccordance with the process conditions listed in Example II;

FIG. 24 is a drawing representing the elevational view in the picture ofFIG. 23 with the respective parts identified by a reference numeral;

FIG. 25 is a picture showing an elevational view of a test semiconductorwafer for Example III after an iridium electrode layer was etched inaccordance with the process conditions listed in Example III;

FIG. 26 is a drawing representing the elevational view in the picture ofFIG. 25 with respective parts identified by a reference numeral;

FIG. 27 is a picture showing an elevational view of a test semiconductorwafer for Example IV after an iridium electrode layer was etched inaccordance with the process conditions listed in Example IV; and

FIG. 28 is a drawing representing the elevational view in the picture ofFIG. 27 with the respective parts identified by a reference numeral.

DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

Referring in detail now to the drawings wherein similar parts of thepresent invention are identified by like reference numerals, there isseen in FIG. 1 a wafer, generally illustrated as 10, having asemiconductor substrate, generally illustrated as 12. The semiconductorsubstrate 12 includes regions of circuit elements which do not appear inthe drawings, but are well known to those skilled in the art. A barrierlayer 14 is disposed over the semiconductor substrate 12 and a layer(i.e., an electrically conductive layer, such as a platinum layer or aniridium layer), generally illustrated as 15, is disposed over thebarrier layer 14. The layer 15 is preferably an electrode layer 16 asshown in FIG. 1. Because the electrode layer 16 is a preferred layer 15,the remaining description of the present invention will use only theterm “electrode layer 16” in describing the present invention. However,it is to be understood that wherever “electrode layer 16” is statedhereinafter, it is to also have the equivalence of “layer 15” forpurposes of the present invention. It is also to be understood that in apreferred embodiment of the present invention “electrode layer 16” maybe a “platinum electrode layer 16” or an “iridium electrode layer 16,”unless otherwise indicated. Thus, whenever “platinum electrode layer 16”is stated or mentioned hereinafter for a preferred embodiment of theinvention, it is be understood that the electrode layer 16 includesplatinum and the preferred embodiment of the present invention relatesto etching platinum to produce the desired features of the presentinvention as set forth hereinafter. Similarly, whenever “iridiumelectrode layer 16” is stated or mentioned hereinafter for a preferredembodiment of the present invention, it is to be understood that theelectrode layer 16 includes iridium and the preferred embodiment of thepresent invention relates to etching iridium to produce the desiredfeatures of the present invention as set forth hereinafter.

Because the electrode layer 16 easily diffuses or reacts with certainelements (e.g. it a poly-Si plug) within the semiconductor substrate 12,the barrier layer 14 is required between the electrode layer 16 and thesemiconductor substrate 12. The barrier layer 14 also functions as anadhesive for coupling the semiconductor substrate 12 to the electrodelayer 16. A mask 18 is disposed over the electrode layer 16 and apatterned resist (i.e. a photoresist), generally illustrated as 20, isselectively positioned on the mask layer 18 as best shown in FIG. 1. Asbest shown in FIG. 1, the patterned resist 20 includes a plurality ofresist members 20 a, 20 b, 20 c, and 20 d. In another preferredembodiment of the invention as shown in FIG. 2, a protective layer 22 isdisposed between the electrode layer 16 and the mask layer 18.

The barrier layer 14 may be any suitable barrier layer which is capableof dually functioning as an adhesive and a diffusion barrier to theelectrode layer 16. The barrier layer 14 may be of any suitablethickness. Preferably, the barrier layer 14 comprises titanium and/or atitanium alloy, such as TiN, and possesses a thickness ranging fromabout 50 Angstroms to about 600 Angstroms, more preferably from about200 Angstroms to about 400 Angstroms, most preferably about 300Angstroms. The barrier layer 14 is preferably disposed on thesemiconductor substrate 12 by the RF magnetron sputtering method.

The electrode layer 16 comprises platinum or iridium as the preferredelectrode material because platinum and iridium are inert to oxidationwhich tends to occur in the subsequent high temperature processes ofdepositing the high dielectric constant ferroelectric materials. Theelectrode layer 16 also comprises platinum or iridium as the preferredelectrode material because platinum and iridium are good electricconductors. The thickness of the electrode layer 16 would depend uponthe end use of the semiconductor or capacitance device which is tocontain the electrode layer 16. Typically, the thickness of the platinumelectrode layer 16 ranges from about 500 Angstroms to about 4000Angstroms, more preferably from about 1000 Angstroms to about 3000Angstroms, most preferably about 2000 Angstroms. The electrode layer 16is preferably disposed on the barrier layer 14 by the RF magnetronsputtering method.

The mask layer 18 may be any suitable insulation or metallic materialthat is capable of being etched in accordance with the proceduredescribed hereinafter such that all traces of the mask layer 18 areessentially removed from the surface electrode layer 16 except thatportion (identified as “18 a,” “18 b,” “18 c,” and “18 d” below) of themask layer 18 remaining under the patterned resist 20. The mask layer 18may also be of any suitable thickness. Preferably, the mask layer 18comprises silicon dioxide (SiO₂) and/or silicon nitride (Si₃N₄) or anyother suitable dielectric material.

In another preferred embodiment of the invention, the mask layer 18comprises Ti and/or TiN, preferably TiN. As will be further explainedbelow, it has been discovered that etching of an iridium electrode layer16 superimposed with a mask layer 18 composing TiN, and in a highdensity plasma of an etchant gas comprising oxygen, a halogen gas (e.g.,Cl₂), and a noble gas (e.g., argon), etched iridium electrodes areproduced having an iridium profile where the angle a of the associatedsidewalls with respect to a horizontal plane is equal to greater thanabout 80 degrees. A clean iridium surface is produced after removal ofthe mask layer 18 with no fence or veil formation. It has been furtherdiscovered, that during etching of the iridium electrode layer 16 in ahigh density plasma of the etchant gas having a gas chemistry ofO₂/halogen gas(es)/noble gas(es), with the iridium electrode layer 16supporting the mask layer 18 comprising TiN, the etch selectivity ofiridium to the TiN is greater than about 8.0, preferably greater thanabout 10.0. It is to be understood that the spirit and scope of thepreent invention includes etching of a platinum electrode layer 16 whilesupporting a mask layer 18 comprising TiN, with the etching of theplatinum electrode layer 16 being conducted in a high density plasma ofan etchant gas comprising oxygen, a halogen gas (e.g., Cl₂), and a noblegas (e.g., argon). A preferred thickness for the mask layer 18 rangesfrom about 500 Angstroms to about 9000 Angstroms, more preferably fromabout 2000 Angstroms to about 7000 Angstroms, most preferably about 3000Angstroms. The mask layer 18 is preferably disposed on the electrodelayer 16 by chemical vapor deposition.

The patterned resist 20 (i.e. the photoresist 20, including resistmembers 20 a, 20 b, 20 c and 20 d) may be any suitable layer ofmaterial(s) that is capable of protecting any underlying material (e.g.the mask layer 18) from being etched during the etching process of thepresent invention. Suitable materials for the patterned resist 20include resist systems consisting of novolac resin and a photoactivedissolution inhibitor (all based on Süiss's discovery). Other suitablematerials for the resist 20 are listed in an article from the July 1996edition of Solid State Technology entitled “Deep-UV Resists: Evolutionand Status” by Hiroshi Ito. The patterned resist 20 may have anysuitable thickness; preferably, the thickness of the patterned resist 20ranges from about 0.3 μm to about 1.40 μm, more preferably from about0.5 μm to about 1.2 μm, most preferably about 0.8 μm. The patternedresist 20 is preferably disposed on the mask layer 18 by the spincoating method.

The protective layer 22 in the embodiment of the invention depicted inFIG. 2 is for protecting the corners (identified as “16 g” below) of anetched electrode layer (generally identified as “16 e” below) during theoveretching process of the present invention. Another purpose of theprotective layer 22 is for providing good adhesion to the mask layer 18and the electrode layer 16. The protective layer 22 may comprise anysuitable materials or chemicals, such as titanium and/or titaniumnitride etc., and may be conveniently disposed on the surface of theelectrode layer 16, such as by the RF magnetron sputtering method. Thethickness of the protective layer 22 may be any suitable thickness,preferably ranging from about 50 Angstroms to about 1000 Angstroms, morepreferably ranging from about 100 Angstroms to about 600 Angstroms, mostpreferably about 300 Angstroms.

In order to form or produce a semiconductor or capacitance device fromthe multilayered structure of FIG. 1 or FIG. 2, the multilayeredstructure is initially placed in a suitable plasma processing apparatusto break through and remove or etch away the mask layer 18 from thesurface of electrode layer 16, except those mask layers 18 a, 18 b, 18 cand 18 d that are respectively below the resist members 20 a, 20 b, 20 cand 20 d, as best shown in FIG. 5, or as best shown in FIG. 6 if theembodiment of the invention depicted in FIG. 2 is being employed.

A suitable prior art plasma processing apparatus is shown in FIG. 3 anddescribed in U.S. Pat. No. 5,188,704 to Babie et al, fully incorporatedherein by reference thereto as if repeated verbatim immediatelyhereinafter. The plasma process apparatus of FIG. 3 comprises a plasmareactor, generally illustrated as 30 and including walls, generallyillustrated as 31 for forming and housing a reactor chamber 32 wherein aplasma 33 of neutral (n) particles, positive (+) particles, and negative(−) particles are found. Walls 31 include cylindrical wall 54 and cover56. Plasma processing gases are introduced via inlets 34 into reactorchamber 32. Plasma etching gases are introduced into chamber 32 throughinlets 44—44. A water cooled cathode 36 is connected to an RF powersupply 38 at 13.56 MHz. An anode 39 is connected to the walls 31 whichare grounded by line 40. Helium gas is supplied through passageway 50through cathode 36 to the space beneath wafer 10 which is supportedperipherally by lip seal 52 so that the helium gas cools the wafer 10.The wafer 10 is supported by a wafer support 46 that includes aplurality of clamps (not shown) which hold down the upper surface ofwafer 10 at its periphery, as is well known to those skilled in the art.A pair of helmholtz configured electromagnetic coils 42 and 43 providenorth and south poles within the chamber 32 and are disposed at oppositeends of the lateral cylindrical wall 54 and the walls 31. Theelectromagnetic coils 42 and 43 provide a transverse magnetic field withthe north and south poles at the left and right providing a horizontalmagnetic field axis parallel to the surface of the wafer 10. Thetransverse magnetic field is applied to slow the vertical velocity ofthe electrons which are accelerated radially by the magnetic field asthey move towards the wafer 10. Accordingly, the quantity of electronsin the plasma 33 is increased by means of the transverse magnetic fieldand the plasma 33 is enhanced as is well known to these skilled in theart.

The electromagnetic coils 42 and 43 which provide the magnetic field areindependently controlled to produce a field intensity orientation whichis uniform. The field can be stepped angularly around the wafer 10 byrotating the energization of the electromagnetic coils 42 and 43,sequentially. The transverse magnetic field provided by theelectromagnetic coils 42 and 43 is directed parallel to the surface ofthe wafer 10 being treated by the plasma 33, and the cathode 36 of theplasma reactor 30 increases ionization efficiently of the electrons inthe plasma 33. This provides the ability to decrease the potential dropacross the sheath of the cathode 36 and to increase the ion current fluxpresent on the surface of the wafer 10, thereby permitting higher ratesof etching without requiring higher ion energies to achieve the resultotherwise.

The preferred magnetic source employed to achieve magnetically enhancedreactive ion etching (MERIE) used in practicing the present invention isa variable rotational field provided by the electromagnetic coils 42 and43 arranged in a Helmholtz configuration. The electromagnetic coils 42and 43 are driven by 3-phase AC currents. The magnetic field with Flux Bis parallel to the wafer 10, and perpendicular to the electrical fieldas shown in FIG. 4. Referring to FIG. 4, the vector of the magneticfield H which produces flux B is rotating around the center axis of theelectrical field by varying the phases of current flowing through theelectromagnetic coils 42 and 43 at a typical rotational frequency of0.01 to 1 Hz, particularly at 0.5 Hz. The strength of the magnetic fluxB typically varies from 0 Gauss to about 150 Gauss and is determined bythe quantities of the currents supplied to the electromagnetic coils 42and 43. While FIG. 3 illustrates one plasma processing apparatus that issuitable for removing the mask layer 18 (except mask layers 18 a, 18 b,18 c and 18 d), it is to be understood that other plasma etchers may beemployed, such as electron cyclotron resonance (ECR), helicon resonanceor inductively coupled plasma (ICP), triode etchers, etc.

The plasma 33 may employ any suitable etchant gas to break through (i.e.to clean and etch away) the mask layer 18 except those mask layers 18 a,18 b, 18 c and 18 d that are respectively below the resist members 20 a,20 b, 20 c and 20 d, as best shown FIGS. 5 and 6. For example, if themask layer 18 contains silicon oxide, suitable etchant gas(es) may beselected from the group consisting of fluorine-containing gases (e.g.CHF₃, SF₆, C₂F₆, NF₃, etc.), bromine-containing gases (e.g. HBr, etc.),chlorine-containing gases (e.g. CHCl₃, etc.), rare or noble gases (e.g.argon, etc.), and mixtures thereof. Preferably and in one preferredembodiment of the invention, the etchant does not include an oxidant,such as oxygen, since the purpose of this step is to remove the masklayer 18 (except those mask layers 18 a, 18 b, 18 c and 18 d which arerespectively protected by resist members 20 a, 20 b, 20 c and 20 d) andnot to remove the patterned resist 20. More preferably, the etchant gascomprises from about 20% by volume to about 40% by volume CHF₃ and fromabout 60% by volume to about 80% by volume argon. The preferred reactorconditions for a suitable plasma processing apparatus (such as theplasma processing apparatus of FIG. 3) in removing the mask layer 18(except mask layers 18 a, 18 b, 18 c and 18 d) are as follows:

Pressure 10-150 mTorr RF Power 500-1500 watts Rotational Magnetic Field25-70 Gauss Temperature of Wafer 25-100° C. Mask Layer 18 Etch Rate2000-10,000 Angstroms/min

The selectivity of mask layer 18 to patterned resist 20 is better than3:1, depending on the materials employed for the mask layer 18 and thepatterned resist 20.

More generally, the process parameters for removing the mask layer 18 ina suitable plasma process apparatus (such as the plasma processingapparatus of FIG. 3) fall into ranges as listed in the following TableIII and based on flow rates of the gases CHF₃ and Ar also listed in thefollowing Table III:

TABLE III Process Broad Preferred Gas Flow, sccm CHF₃ 10 to 50 (20 to40% by vol.) 20 to 40 Ar 50 to 90 (60 to 80% by vol.) 60 to 80 Pressure,mT 10 to 250 10 to 150 13.56 MHz 500 to 2500 500 to 1500 RF Power(Watts) Temperature (° C.) 10 to 120 25 to 100 of Wafer Magnetic Field10 to 120 25 to 70 Gauss

In another preferred embodiment of the invention, when the mask layer 18comprises Ti and/or TiN (preferably TiN), suitable etchant gas(es) tobreak through (i.e., to clean and etch away) the Ti/TiN-containing masklayer 18 except for those mask layers 18 a, 18 b, 18 c and 18 d that arerespectively below the resist numbers 20 a, 20 b, 20 c and 20 d, as bestshown FIGS. 5 and 6, may be selected from the group consisting of anoble gas (e.g., argon), a halogen (e.g., Cl₂), and a gas selected fromthe group consisting of HBr, BCl₃, and mixtures thereof. Preferably, theetchant gas comprises from about 10% by volume to about 30% by volumeargon, from about 20% by volume to about 60% by volume chlorine, andfrom about 20% by volume to about 60% by volume HBr and/or BCl₃. Thepreferred reactor conditions for a suitable plasma processing apparatus(such as the plasma processing apparatus of FIG. 3) in removing the masklayer 18 (except mask layer 18 a, 18 b, 18 c and 18 d) comprising Tiand/or TiN are as follows:

Pressure 10-150 mTorr RF Power 500-1500 watts Rotational Magnetic Field25-70 Gauss Temperature of Wafer 25-100° C. Mask Layer 18 Etch Rate2000-10,000 Angstroms/min

The selectivity of the Ti/TiN-containing mask layer 18 to patternedresist 20 is better than 3:1, depending on the materials employed forthe patterned resist 20.

More generally, the process parameters for removing theTi/TiN-containing mask layer 18 in a suitable plasma process apparatus(such as the plasma processing apparatus of FIG. 3) fall into ranges aslisted in the following Table IV and based on flow rates of the gasesargon, chlorine and HBr and/or BCl₃ also listed in the following TableIV:

TABLE IV Process Broad Preferred Gas Flow, sccm Argon 10 to 50 (10 to30% by vol.) 30 to 40 Chlorine 30 to 100 (20 to 60% by vol.) 60 to 80HBr and/or BCl₃ 30 to 100 (20 to 60% by vol.) 50 to 70 Pressure, mT 10to 250 10 to 150 13.56 MHz 500 to 2500 500 to 1500 RF Power (Watts)Temperature (° C.) 10 to 120 25 to 100 of Wafer Magnetic Field 10 to 12025 to 70 Gauss

For the embodiment of the invention depicted in FIG. 2 wherein theprotective layer 22 is disposed on the electrode layer 16 between themask layer 18 and the electrode layer 16, the protective layer 22 has tobe removed or etched after removal of the mask layer 18 in order toexpose the electrode layer 16. The protective layer 22 may be etched andremoved by any suitable manner and/or with any suitable plasmaprocessing apparatus (such as with the plasma processing apparatus ofFIG. 3) including the plasma 33 employing a suitable etchant gas tobreak through and etch away the protective layer 22 except thoseprotective layers 22 a, 22 b, 22 c and 22 d (see FIGS. 6 and 8)immediately below mask layers 18 a, 18 b, 18 c and 18 d, respectively.For example, if TiN is used as the protective layer 22, suitable etchantgas(es) may be selected from the group consisting of Cl₂, HBr, BCl₃,noble gases (e.g., Ar), and mixtures thereof. Preferably and in oneembodiment of the present invention, the etchant gas for breakingthrough and etching away the protective layer 22, except protectivelayers 22 a, 22 b, 22 c and 22 d, comprises from about 20% by volume toabout 60% by volume Cl₂, from about 20% by volume to about 60% by volumeHBr and/or BCl₃, and from about 10% by volume to about 30% by volume ofa noble gas which is preferably Ar. Suitable reactor conditions for asuitable plasma processing apparatus (such as the plasma processingapparatus of FIG. 3) to remove the protective layer 22 (exceptprotective layers 22 a, 22 b, 22 c and 22 d) may be the same as thosepreviously stated reactor conditions for the removal of the mask layer18 (except mask layers 18 a, 18 b, 18 c and 18 d). It is to beunderstood that other plasma etchers may be employed to remove theprotective layer 20, such as ECR, ICP, Helicon Resonance, etc. As willbe further explained below, the protective layers 22 a, 22 b, 22 c and22 d are for protecting the corners (identified as “16 g” below) of anetched electrode layer (generally identified as “16 e” below) during theetching process of the present invention. It is believed that theprotective layers 22 a, 22 b, 22 c and 22 d not only protect the cornersof an etched electrode layer 16 during the etching process, but alsoassist in maintaining an existing profile and/or improves a profile(i.e., an etched platinum or iridium profile).

In another embodiment of the present invention for etching a platinumelectrode layer 16, the protective layer 22 (except protective layers 22a, 22 b, 22 c and 22 d) may be etched by the high temperatures andetchant gases employed in the platinum-etching process of the presentinvention. More specifically and as will be further explained below,because the platinum electrode layer 16 is preferably etched under thefollowing process conditions in a high density plasma chamber containinga high density inductively coupled plasma:

Process Parameters Etchant Gas flow 50 to 500 sccm Halogen Gas (e.g.,Cl₂) 20% to 95% by vol. Noble Gas (e.g., Ar) 5% to 80% by vol. Pressure,mTorr 0.1 to 300 milliTorr RF Power (watts) 100 to 5000 watts of CoilInductor RF Power (watts) 50 to 3000 watts of Wafer Pedestal Temperature(° C.) of about 150 to about 500° C. Platinum Electrode Wafer PlatinumEtch Rate (Å/min) 200 to 6000 Å/min RF Frequency of 100 K to 300 MHzCoil Inductor RF Frequency of 100 K to 300 MHz Wafer Pedestal

the protective layer 22 may be etched and removed under the sameforegoing conditions. Thus, the same apparatus and process conditionsmay be employed to etch and remove selective parts of the protectivelayer 22, as well as to etch the platinum electrode layer 16. In anotherpreferred embodiment of the present invention and as will be alsofurther explained below,the protective layer 22 and the platinumelectrode layer 16 may be removed and etched respectively in a highdensity plasma chamber containing a high density inductively coupledplasma under the following process conditions:

Process Parameters Etchant Gas flow 50 to 500 sccm Halogen Gas (e.g.,Cl₂) 10% to 90% by vol. Noble Gas (e.g., Ar) 5% to 80% by vol. HBrand/or BCl₃ 45% to 25% by vol. Pressure, mTorr 0.1 to 300 milliTorr RFPower (watts) 100 to 5000 watts of Coil Inductor RF Power (watts) 50 to3000 watts of Wafer Pedestal Temperature (° C.) of about 150 to 500° C.Platinum Electrode Wafer Platinum Etch Rate (Å/min) 200 to 6000 Å/min RFFrequency of 100 K to 300 MHz Coil Inductor RF Frequency of 100 K to 300MHz Wafer Pedestal

In another embodiment of the present invention for etching an iridiumelectrode layer 16, the protective layer 22 (except protective layers 22a, 22 b, 22 c and 22 d) may be etched by the high temperatures andetchant gases employed in the iridium-etching process of the presentinvention. More specifically and as will be further explained below,because the iridium electrode layer 16 is preferably etched under thefollowing process conditions in a high density plasma chamber containinga high density inductively coupled plasma:

Process Parameters Etchant Gas flow 50 to 500 sccm Oxygen 5% to 40% byvol. Halogen Gas (e.g., Cl₂) 10% to 60% by vol. Noble Gas (e.g., Ar) 30%to 80% by vol. Pressure, mTorr 0.1 to 300 milliTorr RF Power (watts) 100to 5000 watts of Coil Inductor RF Power (watts) 50 to 3000 watts ofWafer Pedestal Temperature (° C.) of about 150 to about 500° C. IridiumElectrode Wafer Iridium Etch Rate (Å/min) 200 to 6000 Å/min RF Frequencyof 100 K to 300 MHz Coil Inductor RF Frequency of 100 K to 300 MHz WaferPedestal

the protective layer 22 may be etched under the same foregoingconditions. Thus, the same apparatus and process conditions may beemployed to etch and remove selective parts of the protective layer 22,as well as to etch the iridium electrode layer 16. In another preferredembodiment of the present invention and as will be also furtherexplained below, the protective layer 22 and the iridium electrode layer16 may be removed and etched respectively in a high density plasmachamber containing a high density inductively coupled plasma under thefollowing process conditions:

Process Parameters Etchant Gas flow 50 to 500 sccm Oxygen 5% to 20% byvol. Halogen Gas (e.g., Cl₂) 10% to 60% by vol. Noble Gas (e.g., Ar) 30%to 80% by vol. HBr and/or HCl 5% to 20% by vol. Pressure, mTorr 0.1 to300 milliTorr RF Power (watts) 100 to 5000 watts of Coil Inductor RFPower (watts) 50 to 3000 watts of Wafer Pedestal Temperature (° C.) ofabout 150 to 500° C. Iridium Electrode Wafer Iridium Etch Rate (Å/min)200 to 6000 Å/min RF Frequency of 100K to 300 MHz Coil Inductor RFFrequency of 100K to 300 MHz Wafer Pedestal

After selective parts of the mask layer 18 have been etched away fromthe surface of the electrode layer 16 to expose the latter and such thatthe only remnants of the mask layer 18 are the mask layers 18 a, 18 b,18 c and 18 d situated immediately below the resist members 20 a, 20 b,20 c, and 20 d, respectively, the resist members 20 a, 20 b, 20 c and 20d are to be removed. The resist members 20 a, 20 b, 20 c and 20 d may beremoved at any suitable time, preferably before the etching of theelectrode layer 16 and before the heating of the semiconductor substrate12 to a temperature greater than about 150° C. The same would hold truewith respect to the embodiment of the invention illustrated in FIGS. 2,6 and 8 in that after selective parts of the protective layer 22 havebeen etched away from the surface of the electrode layer 16 to exposethe latter and such that the only remnants of the protective layer 22are the protective layers 22 a, 22 b, 22 c and 22 d situatedrespectively immediately below the mask layers 18 a, 18 b, 18 c and 18d, the resist members 20 a, 20 b, 20 c and 20 d are to be removed.However, with respect to this embodiment of the present invention, theresist members 20 a, 20 b, 20 c and 20 d may be removed before theetching away of selective parts of the protective layer 22.Alternatively, the resist members 20 a, 20 b, 20 c and 20 d may beremoved after (or simultaneously during) the removal of selective partsof the protective layer 22 and before the heating of the semiconductorsubstrate 12 to a temperature greater than about 150° C. for purposes ofetching the electrode layer 16. Typically, at least a portion of theresist members 20 a, 20 b, 20 c and 20 d would be removed whileselective parts of the protective layer 22 are being etched away toexpose the electrode layer 16 that is not superimposed by the protectivelayers 22 a, 22 b, 22 c and 22 d.

The resist members 20 a, 20 b, 20 c and 20 d may be removed in anysuitable manner such as by using oxygen plasma ashing which is wellknown to those skilled in the art. The resist members 20 a, 20 b, 20 cand 20 d may be respectively stripped from the mask layers 18 a, 18 b,18 c and 18 d with any suitable plasma processing apparatus, such as theplasma processing apparatus shown in FIG. 3 and employing a plasmacontaining an etchant gas comprising oxygen. The resist members 20 a, 20b, 20 c and 20 d have been respectively removed from the mask layers 18a, 18 b, 18 c and 18 d in an advanced strip passivation (ASP) chamber ofa plasma processing apparatus sold under the trade mark metal etch MKPCentura to Applied Materials, Inc. 3050 Bowers Avenue, Santa Clara,Calif. 95054-3299. In stripping the resist members 20 a, 20 b, 20 c and20 d from the mask layers 18 a, 18 b, 18 c and 18 d, respectively, theASP chamber may employ microwave downstream O₂/N₂ plasma with thefollowing recipe: 120 seconds, 250° C., 1400 W, 3000 cc O₂, 300 cc N₂and 2 Torr.

After the electrode layer 16 has been exposed as represented in FIGS. 7and 8, it is etched to develop a submicron pattern with a profile. Aswill be further stated below, before the electrode layer 16 is etched,the semiconductor substrate 12 supporting the electrode layer 16 isheated to a temperature greater than about 150° C., preferably greaterthan about 150° C. up to about 500° C., more preferably from about 200°C. to about 400° C., most preferably from about 250° C. to about 350° C.The semiconductor substrate 12 is preferably heated by the pedestalwhich supports the wafer 10 during the etching process.

The electrode layer 16 may be etched in any suitable plasma processingapparatus, such as in the reactive ion etch (RIE) plasma processingapparatus sold under the trademark AME8100 Etch™, or under the trademarkPrecision Etch 5000™, or under the trademark Precision Etch 8300™, alltrademarks owned by Applied Materials Inc., 3050 Bowers Avenue, SantaClara, Calif. 95054-3299. Another suitable plasma processing apparatusfor etching the electrode layer 16 is that plasma processing apparatussold under the trademark Metal Etch DPS Centura™ also owned by AppliedMaterials, Inc. It is also to be understood that other plasma etchersmay be employed, such as ECR, ICP, Helicon Resonance, etc.

A suitable plasma processing apparatus for etching the electrode layer16 employs a plasma of an etchant gas, which is capable of producinggood profiles (e.g. platinum or iridium profiles) equal to or greaterthan about 85 degrees, preferably equal to or greater than about 87degrees, more preferably equal to or greater than about 88.5 degrees.The etchant gas broadly comprises, or consists of or consistsessentially of, a halogen containing gas, such as a halogen gas (e.g.,fluorine, chlorine, bromine, iodine, and astatine) and a noble gas suchas helium, neon, argon, krypton, xenon, and radon. Preferably, theetchant gas comprises or consists of or consists essentially of ahalogen (preferably chlorine) and a noble gas selected from the groupconsisting of helium, neon, and argon. The noble gas is preferablyargon. The etchant gas more specifically comprises, or consists of orconsists essentially of, preferably from about 20% by volume to about95% by volume of the halogen gas (i.e., chlorine) and from about 5% byvolume to about 80% by volume of the noble gas (i.e., argon); morepreferably from about 40% by volume to about 80% by volume of thehalogen gas (i.e., chlorine) and from about 20% by volume to about 60%by volume of the noble gas (i.e., argon); most preferably from about 55%by volume to about 65% by volume of the halogen gas (i.e., chlorine) andfrom about 35% by volume to about 45% by volume of the noble gas (i.e.,argon).

The etchant gas may also broadly comprise oxygen, a halogen containinggas, such as a halogen gas (e.g., fluorine, chlorine, bromine, iodine,and astatine), and a noble gas such as helium, neon, argon, krypton,xenon, and radon. Preferably, the etchant gas comprises, or consists ofor consists essentially of, a halogen (preferably chlorine) and a noblegas selected from the group consisting of helium, neon and argon. Thenoble gas is preferably argon. The etchant gas more specificallycomprises, or consists of or consists essentially of, preferably fromabout 5% by volume to about 40% by volume oxygen, from about 10% byvolume to about 60% by volume of the halogen gas (i.e., chlorine), andfrom about 30% by volume to about 80% by volume of the noble gas (i.e.,argon); more preferably from about 10% by volume to about 30% by volumeoxygen, from about 20% by volume to about 50% by volume of the halogengas (i.e., chlorine), and from about 40% by volume to about 70% of thenoble gas (i.e., argon); most preferably from about 10% by volume toabout 20% by volume oxygen, from about 20% by volume to about 30% byvolume halogen gas (i.e., chlorine), and from about 50% by volume toabout 70% by volume of noble gas (i.e., argon).

In another preferred embodiment of the invention, the etchant gascomprises, preferably consists of or consists essentially of, thehalogen (i.e., chlorine), the noble gas (i.e., argon), and a gasselected from the group consisting of HBr, BCl₃ and mixtures thereof.The etchant gas more specifically comprises, or consists of or consistsessentially of, from about 10% by volume to about 90% by volume of thehalogen gas (i.e., chlorine) and from about 5% by volume to about 80% byvolume of the noble gas (i.e., argon) and from about 4% by volume toabout 25% by volume of HBr and/or BCl₃; preferably from about 40% byvolume to about 70% by volume of the halogen gas (i.e., chlorine) andfrom about 25% by volume to about 55% by volume of the noble gas (i.e.,argon) and from about 5% by volume to about 20% by volume of HBr and/orBCl₃; and more preferably from about 50% by volume to about 60% byvolume of the halogen gas (i.e., chlorine) and from about 35% by volumeto about 45% by volume of the noble gas (i.e., argon) and from about 5%by volume to about 15% by volume of HBr and/or BCl₃. The etchant gasflow rate ranges from about 50 sccm to about 500 sccm. HBr and/or BCl₃are for removal of residue (e.g., platinum or iridium residue) duringetching of the electrode layer 16. Plasmas containing argon are known tohave a high energetic ion concentration and are often used for physicalsputtering. The sputtering effect due to the ions is a function of theaccelerating potential which exist between the plasma and the sample.

In a further preferred embodiment of the invention, the etchant gascomprises, preferably consists of or consists essentially of, oxygen,the halogen (i.e., chlorine), the noble gas (i.e., argon), and a gasselected from the group consisting of HBr, HCl and mixtures thereof. Theetchant gas more specifically comprises, or consists of or consistsessentially of, from about 5% by volume to about 20% by volume oxygen,from about 10% by volume to about 60% by volume of the halogen gas(i.e., chlorine) and from about 30% by volume to about 80% by volume ofthe noble gas (i.e., argon) and from about 5% by volume to about 20% byvolume of HBr and/or HCl; preferably from about 5% by volume to about15% by volume oxygen, from about 20% by volume to about 50% by volume ofthe halogen gas (i.e., chlorine) and from about 40% by volume to about70% by volume of the noble gas (i.e., argon) and from about 5% by volumeto about 15% by volume of HBr and/or HCl; and more preferably from about5% by volume to about 10% by volume oxygen, from about 20% by volume toabout 35% by volume of the halogen gas (i.e., chlorine) and from about40% by volume to about 60% by volume of the noble gas (i.e., argon) andfrom about 5% by volume to about 10% by volume of HBr and/or HCl. Theetchant gas flow rate ranges from about 50 sccm to about 500 sccm.

The reactor conditions for a suitable plasma processing apparatus, suchas the plasma processing apparatus of FIG. 3, in etching the electrodelayer 16 are as follows:

Pressure 0.1˜300 mTorr RF Power 100-5000 watts Rotational Magnetic Field20˜100 Gauss Temperature of Wafer about 150-about 500° C. Platinum Layer16 Etch Rate 200-6000 Angstroms/min

The selectivity of electrode layer 16 to mask 18 is better than 2:1,depending on the materials employed for the patterned resist 18.

More generally, the process parameters for etching the electrode layer16 in a suitable plasma processing apparatus, such as the plasmaprocessing apparatus of FIG. 3, fall into ranges as listed in thefollowing Table V and based on the flow rate of etchant gas as alsolisted in Table V below:

TABLE V Process Broad Preferred Optimum Gas Flow, sccm Etchant Gas  50to 500  75 to 250 100 to 200 Pressure, mT  20 to 2000  30 to 300  50 to150 13.56 MHz  50 to 3000 500 to 2000 700 to 1200 RF Power (Watts)Temperature (° C.) of 150 to 500 200 to 400 250 to 350 Wafer MagneticField Gauss  0 to 140  20 to 100  60 to 80

As previously indicated, a preferred etchant gas for etching theplatinum electrode layer 16 is a mixture of chlorine and argon, or amixture of chlorine, argon and HBr and/or BCl₃. Another preferredetchant gas for etching the electrode layer 16 is a mixture of oxygen,chlorine and argon, or a mixture of oxygen, chlorine, argon and HBrand/or HCl. If the etchant gas is a mixture of chlorine and argon (i.e.,from about 20% by volume to about 95% by volume chlorine and from about5% by volume to about 80% by volume argon), or a mixture of oxygen,chlorine and argon (i.e., from about 5% to about 40% by volume oxygen,from about 10% to about 60% by volume chlorine, and from about 30% toabout 80% by volume argon), or a mixture of chlorine, argon and HBrand/or BCl₃ (i.e., from about 10% by volume to about 90% by volumechlorine and from about 5% by volume to about 80% by volume argon andfrom about 4% by volume to about 25% by volume HBr and/or BCl₃), or amixture of oxygen, chlorine, argon and HBr and/or HCl (i.e., from about5% to about 20% by volume oxygen, from about 10% to about 60% by volumechlorine, from about 30% to about 80% by volume argon, and from about 5%to about 20% by volume HBr and/or HCl), and if the semiconductorsubstrate 12 is heated to a temperature greater than about 150° C.,preferably to a temperature ranging from about 150° C. to about 500° C.,the plasma processing apparatus for etching the electrode layer 16(i.e., a platinum electrode layer 16 or an iridium electrode layer 16)etches the electrode layer 16 in a high density plasma of the etchantgas at a high etch rate (i.e. an etch rate higher than 700 Å/min foriridium, and an etch rate higher than 1000 Å/min for platinum) andproduces an etched electrode layer, generally illustrated as 16 e (asbest shown in FIGS. 9 and 10). The etched platinum electrode layer 16 e(i.e., etched platinum electrode layer 16 e or etched iridium electrodelayer 16 e) includes etched electrode layers 16 a, 16 b, 16 c and 16 d(i.e., etched platinum or iridium electrode layers 16 a, 16 b, 16 c and16 d) having corners 16 g and sidewalls 16 s and an excellent profile(i.e., an excellent platinum or iridium profile); that is, a profilewhere the angle ∝ of the sidewalls 16 s (as also best shown in FIGS. 9and 10) with respect to a horizontal plane is equal to or greater thanabout 80 degrees for iridium, and equal to or greater than about 85degrees for platinum, preferably equal to or greater than about 87°, andmore preferably equal to or greater than about 88.5°. The producedelectrodes (i.e., produced platinum electrodes) are separated by adistance or space having a dimension equal to or less than about 0.3 μm.Each of the electrodes include a dimension having a value equal to orless than about 0.6 μm, preferably equal to or less than about 0.3 μm.More preferably, each of the electrodes have a width equal to or lessthan about 0.6 μm, and a height equal to or less than about 0.6 μm.

It has also been discovered that the etched electrode layer 16 e (i.e.,etched electrode layers 16 a, 16 b, 16 c and 16 d) has essentially nowall-like structures extending up from the edges of the electrode region(i.e., the platinum region or the iridium region). These wall-likestructures are frequently referred to as “veils” or “fences” or “rabbitears.” Therefore, the method of the present invention produces etchedelectrode layers 16 a, 16 b, 16 c and 16 d which are essentiallyveil-less. Because the produced etched electrode layers 16 a, 16 b, 16 cand 16 d are essentially veil-less and have no “fences” or “rabbitears,” they are ideally suited for receiving a dielectric BST or PZTlayer and functioning as electrodes in a semiconductor device (i.e., acapacitance structure).

The high density plasma of the present invention may be defined as aplasma of the etchant gas of the present invention having an ion densitygreater than about 10⁹/cm³, preferably greater than about 10¹¹/cm³. Thesource of the high density plasma may be any suitable high densitysource, such as electron cyclotron resonance (ECR), helicon resonance orinductively coupled plasma (ICP)-type sources. All three are in use onproduction equipment today. The main difference is that ECR and heliconsources employ an external magnetic field to shape and contain theplasma, while ICP sources do not.

The high density plasma for the present invention is more preferablyproduced or provided by inductively coupling a plasma in a decoupledplasma source etch chamber, such as that sold under the trademark DPS™owned by Applied Materials, Inc. which decouples or separates the ionflux to the wafer 10 and the ion acceleration energy. The design of theetch chamber provides fully independent control of ion density of anenlarged process window. This is accomplished by producing plasma via aninductive source. While a cathode within the etch chamber is stillbiased with rf electric fields to determine the ion acceleration energy,a second rf source (i.e. an inductive source) determines the ion flux.This second rf source is not capacitive (i.e. it does not use electricfields like the cathode) since a large sheath voltage would be produced,interfering with the cathode bias and effectively coupling the ionenergy and ion flux.

The inductive plasma source couples rf power through a dielectric windowrather than an electrode. The power is coupled via rf magnetic fields(not electric fields) from rf current in a coil. These rf magneticfields penetrate into the plasma and induce rf electric fields(therefore the term “inductive source”) which ionize and sustain theplasma. The induced electric fields do not produce large sheath voltageslike a capacitive electrode and therefore the inductive sourcepredominantly influences ion flux. The cathode bias power plays littlepart in determining ion flux since most of the rf power (typically anorder of magnitude less than the source power) is used in acceleratingions. The combination of an inductive plasma source and a capacitivewafer bias allows independent control of the ion flux and ion energyreaching the wafer 10 in the etch chamber, such as the DPST™ brand etchchamber.

DPST™ brand etch chambers for producing the high density plasma of thepresent invention for etching the electrode layer 16 to produce theetched electrode layers 16 a, 16 b, 16 c and 16 d may be any of the DPS™brand etch chambers of the inductively coupled plasma reactor disclosedin U.S. Pat. No. 5,753,044, issued May 19, 1998, entitled “RF PLASMAREACTOR WITH HYBRID CONDUCTOR AND MULTI-RADIUS DOME CEILING” andassigned to the present assignee and fully incorporated herein byreference thereto as if repeated verbatim immediately hereinafter.Referring now to FIGS. 17 and 18 for two (2) embodiments of aninductively coupled plasma reactor from U.S. Pat. No. 5,753,044 there isseen an inductively coupled RF plasma reactor generally illustrated as90, having a reactor chamber, generally illustrated as 92, wherein ahigh density plasma 94 of neutral (n) particles, positive (+) particles,and negative (−) particles are found. The reactor chamber 92 has agrounded conductive cylindrical sidewall 60 and a dielectric ceiling 62.The inductively coupled RF plasma reactor 90 further comprises a waferpedestal 64 for supporting the (semiconductor) wafer 10 in the center ofthe chamber 92, a cylindrical inductor coil 68 surrounding an upperportion of the chamber 92 beginning near the plane of the top of thewafer 10 or wafer pedestal 64 and extending upwardly therefrom towardthe top of the chamber 92, an etching gas source 72 and gas inlet 74 forfurnishing an etching gas into the interior of the chamber 92, and apump 76 for controlling the pressure in the chamber 92. The coilinductor 68 is energized by a plasma source power supply or RF generator78 through a conventional active RF match network 80, the top winding ofthe coil inductor 68 being “hot” and the bottom winding being grounded.The wafer pedestal 64 includes an interior conductive portion 82connected to the bias RF power supply or generator 84 and an exteriorgrounded conductor 86. (insulated from the interior conductive portion82). Thus, the plasma source power applied to the coil inductor 68 bythe RF generator 78 and the DC bias RF power applied to the waferpedestal 64 by generator 84 are separately controlled RF supplies.Separating the bias and source power supplies facilitates independentcontrol of ion density and ion energy, in accordance with well-knowntechniques. To produce high density plasma 94 as an inductively coupledplasma, the coil inductor 68 is adjacent to the chamber 92 and isconnected to the RF source power supply or the RF generator 78. The coilinductor 68 provides the RF power which ignites and sustains the highion density of the high density plasma 94. The geometry of the coilinductor 68 can in large part determine spatial distribution of theplasma ion density of the high density plasma 94 within the reactorchamber 92.

Uniformity of the plasma density spatial distribution of the highdensity plasma 94 across the wafer 10 is improved (relative to conicalor hemispherical ceilings) by shaping the ceiling 62 in a multi-radiusdome and individually determining or adjusting each one of the multipleradii of the ceiling 62. The multiple-radius dome shape in theparticular embodiment of FIG. 17 somewhat flattens the curvature of theceiling 62 around the center portion of the ceiling 62, the peripheralportion of the ceiling 62 having a steeper curvature.

As illustrated in FIG. 18 the coil inductor 68 may be coupled to the RFpower source 78, 80 in a mirror coil configuration that is known tothose skilled in the art. In the mirror coil configuration of FIG. 18,the RF source 78, 80 is connected to the center winding of the coilinductor 68 while the top and bottom ends of the coil inductor 68 areboth grounded. The mirror coil configuration has the advantage ofreducing the maximum potential on the coil inductor 68.

It has been discovered that by employing a high density plasma, such asthe high density plasma 94 illustrated in FIGS. 17 and 18, for etchingthe electrode layer 16 (i.e., a platinum electrode layer 16 or aniridium electrode layer 16), and by heating the semiconductor substrate12 to a temperature greater than about 150° C. before conducting theetching operation under process parameters which are stated below, asemiconductor device is produced with electrodes (i.e., platinumelectrodes or iridium electrodes) having a profile with an angular valuewhich is equal to or greater than about 80 degrees for iridium, andequal to or greater than about 85 degrees for platinum, more preferablyequal to or greater than about 87 degrees, most preferably equal to orgreater than about 88.5 degrees. The electrodes are essentiallyveil-less; that is, they have no “fences” or “rabbit ears.” Theelectrodes are preferably separated by a distance or space having adimension equal to or less than about 0.3 μm. Each of the electrodesinclude a dimension having a value equal to or less than about 0.6 μm,preferably equal to or less than about 0.3 μm. More preferably, each ofthe electrodes have a width equal to or less than about 0.3 μm, a lengthequal to or less than about 0.6 μm, and a height equal to or less thanabout 0.6 μm.

The preferred reactor conditions for a suitable inductively coupled RFplasma reactor, such as the inductively coupled RF plasma reactor 90 inFIGS. 17 and 18, in etching the electrode layer 16 are as follows:

Pressure 0.1 to 300 mTorr RF Power to 100 to 5000 watts Coil Inductor RFPower to 50 to 3000 watts Wafer Pedestal RF Frequency in 100K to 300 MHzCoil Inductor RF Frequency in 100K to 300 MHz Wafer Pedestal Temperatureof Wafer 150 to 500° C. Platinum Etch Rate 200 to 6000 Angstrom/min

More generally, the process parameters for etching the electrode layer16 in a suitable inductively coupled plasma reactor, such as theinductively coupled plasma reactor 90 in FIGS. 17 and 18, fall intoranges as listed on the basis of flow rates of the gases, including thehalogen gas(es) (i.e., Cl₂) and the noble gas(es) (i.e., argon), aslisted in Table VI below.

TABLE VI Process Broad Preferred Optimum Gas Flow, sccm Cl₂ 30 to 400 50to 250 60 to 150 Ar 20 to 300 30 to 200 40 to 100 Pressure, mT 0.1 to300 10 to 100 10 to 40 RF Power of Coil 100 to 5000 650 to 2000 900 to1500 Inductor (Watts) RF Power of Wafer 50 to 3000 100 to 1000 150 to400 Pedestal (Watts) Temperature of Wafer about 150 200 to 400 250 to350 (° C.) to about 500 Etch Rate (Å/min) 200 to 6000 500 to 3000 1000to 2000 RF Frequency of Coil 100K to 300 400K to 20 2 to 13.5 InductorMHz MHz MHz RF Frequency of Wafer 100K to 300 400K to 20 400K to 13.5Pedestal MHz MHz MHz

Also generally, the process parameters for etching the electrode layer16 in a suitable inductively coupled plasma reactor, such as theinductively coupled plasma reactor 90 in FIGS. 17 and 18, fall intoranges as listed on the basis of flow rates of the gases, includingoxygen, the halogen gas(es) (i.e., Cl₂), and the noble gas(es) (i.e.,argon), as listed in Table VII below.

TABLE VII Process Broad Preferred Optimum Gas Flow, sccm O₂ 10 to 60 10to 40 15 to 30 Cl₂ 30 to 100 30 to 70 50 to 70 Ar 50 to 250 100 to 200100 to 150 Pressure, mT 0.1 to 300 10 to 100 10 to 40 RF Power of Coil100 to 5000 650 to 2000 900 to 1500 Inductor (Watts) RF Power of Wafer50 to 3000 100 to 1000 150 to 600 Pedestal (Watts) Temperature of Waferabout 150 to 200 to 400 250 to 350 (° C.) about 500 Etch Rate (Å/min)200 to 6000 500 to 3000 500 to 2000 RF Frequency of Coil 100K to 300400K to 20 2 to 13.5 Inductor MHz MHz MHz RF Frequency of Wafer 100K to300 400K to 20 400K to 13.5 Pedestal MHz MHz MHz

More generally further, and when the etchant gases are a mixture of thehalogen gas(es) (i.e., chlorine), the noble gas(es) (i.e., argon), andHBr and/or BCl₃, the process parameters for etching the electrode layer16 in a suitable inductively coupled plasma reactor, such as theinductively coupled plasma reactor 90 in FIGS. 17 and 18, fall into theranges as listed on the basis of flow rates of the gases, including thehalogen gas(es) (i.e., Cl₂) and the noble gas(es) (i.e., Ar) and HBrand/or BCl₃, as listed in Table VIII below:

TABLE VIII Process Broad Preferred Optimum Gas Flow, sccm Cl₂ 30 to 40050 to 250 60 to 150 Ar 20 to 300 30 to 200 40 to 100 HBr and/or BCl₃ 5to 70 5 to 40 5 to 20 Pressure, mT 0.1 to 300 10 to 100 10 to 40 RFPower of Coil 100 to 5000 650 to 2000 750 to 1000 Inductor (Watts) RFPower of Wafer 50 to 3000 100 to 1000 150 to 400 Pedestal (Watts)Temperature of Wafer about 150 to 200 to 400 250 to 350 (° C.) about 500Etch Rate (Å/min) 200 to 6000 500 to 3000 1000 to 2000 RF Frequency ofCoil 100K to 300 400K to 20 2 to 13.5 Inductor MHz MHz MHz RF Frequencyof Wafer 100K to 300 400K to 20 400 K to 13.5 Pedestal MHz MHz MHz

Also more generally further, and when the etchant gases are a mixture ofoxygen, the halogen gas(es) (i.e., chlorine), the noble gas(es) (i.e.,argon), and HBr and/or BCl₃, the process parameters for etchingelectrode layer 16 in a suitable inductively coupled plasma reactor,such as the inductively coupled plasma reactor 90 in FIGS. 17 and 18,fall into the ranges as listed on the basis of rates of the gases,including oxygen, the halogen gas(es) (i.e., Cl₂), the noble gas(ses)(i.e., Ar), and HBr and/or HCl, as listed in Table IX below:

TABLE IX Process Broad Preferred Optimum Gas Flow, sccm O₂ 10 to 60 10to 40 15 to 30 Cl₂ 30 to 100 30 to 70 50 to 70 Ar 50 to 250 100 to 200100 to 150 HBr and/or HCl 10 to 60 10 to 40 15 to 30 Pressure, mT 0.1 to300 10 to 100 10 to 40 RF Power of Coil 100 to 5000 650 to 2000 750 to1000 Inductor (Watts) RF Power of Wafer 50 to 3000 100 to 1000 150 to600 Pedestal (Watts) Temperature of Wafer about 150 to 200 to 400 250 to350 (° C.) about 500 Etch Rate (Å/min) 200 to 6000 500 to 3000 500 to2000 RF Frequency of Coil 100K to 300 400K to 20 2 to 13.5 Inductor MHzMHz MHz RF Frequency of Wafer 100K to 300 400K to 20 400 K to 13.5Pedestal MHz MHz MHz

Therefore, the foregoing process conditions are preferably based on flowrates of etchant gas(es) having a flow rate value ranging from about 5to about 500 sccm. It will be appreciated by those skilled in the artthat the process parameters of Tables V and VI, as well as other processparameters described herein, may vary in accordance with the size of thewafer 10. As was previously mentioned, the etchant gas comprises orconsists of or consists essentially of a halogen (preferably chlorine)and a noble gas selected from the group consisting of helium, neon, andargon. In another preferred embodiment of the invention, the etchant gascomprises, or consists of or consists essentially of, oxygen, a halogen(preferably chlorine), and a noble gas selected from the groupconsisting of helium, neon, and argon. The noble gas is preferablyargon. As was also previously mentioned, the etchant gas morespecifically-comprises, or consists of or consists essentially of, fromabout 20% by volume to about 95% by volume of the halogen gas (i.e.,chlorine) and from about 5% by volume to about 80% by volume of thenoble gas (i.e., argon); preferably from about 40% by volume to about80% by volume of the halogen gas (i.e., chlorine) and from about 20% byvolume to about 60% by volume of the noble gas (i.e., argon); morepreferably from about 55% by volume to about 65% by volume of thehalogen gas (i.e., chlorine) and from about 35% by volume to about 45%by volume of the noble gas (i.e., argon). As was further previouslymentioned, the etchant gas more specifically comprises, or consists ofor consists essentially of, from about 5% by volume to about 40% byvolume oxygen, from about 10% by volume to about 60% by volume of thehalogen gas (i.e., chlorine) and from about 30% by volume to about 80%by volume of the noble gas (i.e., argon); preferbly from about 10% byvolume to about 30% by volume oxygen, from about 20% by volume to about50% by volume of the halogen gas (i.e., chlorine) and from about 40% byvolume to about 70% by volume of the noble gas (i.e., argon); morepreferably from about 10% by volume to about 20% by volume oxygen, fromabout 20% by volume to about 30% by volume of the halogen gas (i.e.,chlorine) and from about 50% by volume to about 70% by volume of thenoble gas (i.e., argon). In yet another preferred embodiment of theinvention and as was previously mentioned, the etchant gas comprises,preferably consists of or consists essentially of, the halogen (i.e.,chlorine), the noble gas (i.e., argon), and a gas selected from thegroup consists of HBr, BCl₃ and mixtures thereof. In also yet anotherpreferred embodiment of the invention and as was previously mentioned,the etchant gas comprises, preferably consists of or consistsessentially of, oxygen, the halogen (i.e., chlorine), the noble gas(i.e., argon), and a gas selected from the group consists of HBr, BCl₃and mixtures thereof. The etchant gas more specifically comprises, orconsists of or consists essentially of from about 10% by volume to about90% by volume of the halogen gas (i.e., chlorine) and from about 5% byvolume to about 80% by volume of the noble gas (i.e., argon) and fromabout 4% by volume to about 25% by volume of HBr and/or BCl₃; preferablyfrom about 40% by volume to about 70% by volume of the halogen gas(i.e., chlorine) and from about 25% by volume to about 55% by volume ofthe noble gas (i.e., argon) and from about 5% by volume to about 20% byvolume of HBr and/or BCl₃; and more preferably from about 50% by volumeto about 60% by volume of the halogen gas (i.e., chlorine) and fromabout 35% by volume to about 45% by volume of the noble gas (i.e.,argon) and from about 5% by volume to about 15% by volume of HBr and/orBCl₃. As was also yet further previously mentioned, the etchant gas morespecifically comprises, or consists of or consists essentially of, fromabout 5% by volume to about 20% by volume oxygen, from about 10% byvolume to about 60% by volume of the halogen gas (i.e., chlorine) andfrom about 30% by volume to about 80% by volume of the noble gas (i.e.,argon) and from about 5% by volume to about 20% by volume of HBr and/orHCl; preferably from about 5% by volume to about 15% by volume oxygen,from about 20% by volume to about 50% by volume of the halogen gas(i.e., chlorine), from about 40% by volume to about 70% by volume of thenoble gas (i.e., argon) and from about 5% by volume to about 15% byvolume of HBr and/or HCl; and more preferably from about 5% by volume toabout 10% by volume oxygen, from about 20% by volume to about 35% byvolume of the halogen gas (i.e., chlorine) and from about 40% by volumeto about 60% by volume of the noble gas (i.e., argon) and from about 5by volume to about 10% by volume of HBr and/or HCl. Thus, the foregoingrespective process conditions stated in Tables VI through IX may bebased on such etchant gas constituency and on such percent (%) by volumevalue(s).

In the preferred embodiment of the present invention where the masklayers 18 a, 18 b, 18 c and 18 d comprise Ti and/or TiN, preferablyTiN₁, and the electrode layer 16 is an iridium electrode layer 16, theprocess parameters for etching the iridium electrode layer 16 in asuitable inductively coupled plasma reactor fall into ranges as listedon the basis of flow rates of the gases, including oxygen, the halogengas(es), (i.e., Cl₂), and the noble gas(es) (i.e., argon), as listed inTable X below.

TABLE X Process Broad Preferred Optimum Gas Flow, sccm O₂ 10 to 60 10 to40 15 to 30 Cl₂ 30 to 100 30 to 70 50 to 70 Ar 50 to 250 100 to 200 100to 150 Pressure, mT 0.1 to 300 10 to 100 10 to 40 RF Power of Coil 100to 5000 650 to 2000 750 to 1000 Inductor (Watts) RF Power of Wafer 50 to3000 100 to 1000 150 to 600 Pedestal (Watts) Temperature of Wafer about150 to 200 to 400 250 to 350 (° C.) about 500 Iridium (Ir) Etch Rate 200to 6000 500 to 3000 500 to 2000 (Å/min) Selectively of Ir to Ti or 0.2to 50 1 to 20 6 to 10 TiN of Mask Layers RF Frequency of Coil 100K to300 400K to 20 2 to 13.5 Inductor MHz MHz MHz RF Frequency of Wafer 100Kto 300 400K to 20 400K to 13.5 Pedestal MHz MHz MHz

When the etchant gases are a mixture of oxygen, the halogen gas(es)(i.e., chlorine), the noble gas(es) (i.e., argon), and HBr and/or HCl,the process parameters for etching iridium electrode layer 16 supportinga Ti/TiN mask layer 18 in a suitable inductively coupled plasma reactorfall into the ranges as listed on the basis of rates of the gases,including oxygen, the halogen gas(es) (i.e., Cl₂), the noble gas(ses)(i.e., Ar), and HBr and/or HCl, as listed in Table XI below:

TABLE XI Process Broad Preferred Optimum Gas Flow, sccm O₂ 10 to 60 10to 40 15 to 30 Cl₂ 30 to 100 30 to 70 50 to 70 Ar 50 to 250 100 to 200100 to 150 HBr and/or HCl 10 to 60 10 to 40 15 to 30 Pressure, mT 0.1 to300 10 to 100 10 to 40 RF Power of Coil 100 to 5000 650 to 2000 750 to1000 Inductor (Watts) RF Power of Wafer 50 to 3000 100 to 1000 150 to600 Pedestal (Watts) Temperature of Wafer about 150 to 200 to 400 250 to350 (° C.) about 500 Iridium Etch Rate 200 to 6000 500 to 3000 500 to2000 (Å/min) Selectivity of Ir to Ti or 0.2 to 50 1 to 20 6 to 10 TiN ofMask Layers RF Frequency of Coil 100K to 300 400K to 20 2 to 13.5Inductor MHz MHz MHz RF Frequency of Wafer 100K to 300 400K to 20 400Kto 13.5 Pedestal MHz MHz MHz

For the embodiment of the invention illustrated in FIGS. 2, 6, 8 and 10,the protective layers 22 a, 22 b, 22 c and 22 d protect the corners 16 gof the etched electrode layers 16 a, 16 b, 16 c and 16 d during theetching process. Typically and as best shown in FIGS. 11 and 12, some ofthe mask layers 18 a, 18 b, 18 c and 18 d would be etched during theetching process, leaving residual mask layers 18 r on top of etchedelectrode layers 16 a, 16 b, 16 c and 16 d, or on top of the protectivelayers 22 a, 22 b, 22 c and 22 d. The protective layers 22 a, 22 b, 22 cand 22, respectively, insure that the corners 16 g of the etchedelectrode layers 16 a, 16 b, 16 c and 16 d are protected during etching,especially in the event that the etching process removes essentially allof the mask layers 18 a, 18 b, 18 c and 18 d. Maintaining the corners 16g of the etched electrode layers 16 a, 16 b, 16 c and 16 d protects thequality of the profile formed during etching of the electrode layer 16to produce the etched electrode layers 16 a, 16 b, 16 c and 16 d.

After the electrode layer 16 has been etched to produce the electrodelayers 16 a, 16 b, 16 c and 16 d, the residual mask layers 18 r (if notcompletely removed during the etching process) typically remain on topof the veil-less etched electrode layers 16 a, 16 b, 16 c and 16 d, oron top of the protective layers 22 a, 22 b, 22 c and 22 d which arerespectively supported by the essentially veil-less etched electrodelayers 16 a, 16 b, 16 c and 16 d, all as best shown in FIGS. 11 and 12.The residual mask layers 18 r are to be removed by any suitable meansand/or in any suitable manner, such is by CHF₃/Ar plasma. If theresidual masks layers 18 r comprise Ti and/or TiN, the residual masklayers 18 r may be removed by any suitable means and/or in any suitablemanner, such as by the conditions given in Table IV above. Likewise forthe embodiment of the invention depicted in FIG. 12, the protectivelayers 22 a, 22 b, 22 c and 22 d are to be removed after removal of theresidual mask layers 18 r from the protective layers 22 a, 22 b, 22 cand 22 d. The protective layers 22 a, 22 b, 22 c and 22 d may be removedby any suitable means and/or in any suitable manner. For example, whenthe protective layers 22 a, 22 b, 22 c and 22 d comprise TiN removal isby Ar/Cl₂ plasma in a DPS™ brand chamber of the Metal Etch DPS Centura™brand plasma processing apparatus under the following apparatus andprocess conditions as listed in Table XII below.

TABLE XII Process Broad Preferred Optimum Gas Flow, sccm Cl₂ 20 to 15030 to 120 40 to 100 Ar 20 to 100 30 to 80 40 to 60 Pressure, mT 0.5 to40 4 to 30 7 to 14 RF Power of Coil 500 to 3000 500 to 2000 800 to 1200Inductor (Watts) RF Power of Wafer 50 to 500 50 to 300 50 to 150Pedestal (Watts) Temperature of Wafer 20 to 500 20 to 150 80 to 130 TiNEtch Rate (Å/min) 500 to 5000 1000 to 3500 1500 to 2500 RF Frequency ofCoil 100K to 300 400K to 20 2 to 13.5 Inductor MHz MHz MHz RF Frequencyof Wafer 100K to 300 400K to 20 400K to 13.5 Inductor MHz MHz MHz

After removal of residual mask layers 18 r, or the residual mask layers18 r and the protective layers 22 a, 22 b, 22 c and 22 d for theembodiment of the invention illustrated in FIG. 12, the veil-less etchedelectrode layered structure of FIG. 13 or FIG. 14 remains. It should benoted, as best shown in FIGS. 15 and 16, respectively, that the barrierlayer 14 could be etched simultaneously during or after removal of theresidual mask layers 18 r (see FIG. 15), or etched simultaneously duringor after removal of the residual mask layers 18 r and the protectivelayers 22 a, 22 b, 22 c and 22 d (see FIG. 16).

It is to be understood that the patterned resist 20 (i.e., resistmembers 20 a, 20 b, 20 c and 20 d) for the embodiment of the inventiondepicted in FIG. 1, or the patterned resist 20 (i.e., resist numbers 20a, 20 b, 20 c and 20 d) and/or the mask layers 18 a, 18 b, 18 c and 18 dfor the embodiment of the invention depicted in FIG. 2, may be removedat any suitable time, preferably before the etching of the electrodelayer 16. Similarly, the protective layers 22 a, 22 b, 22 c and 22 dand/or mask layers 18 a, 18 b, 18 c and 18 d for the embodiment of theinvention depicted in FIG. 2, may also be removed at any suitable time,such as during the etching process or after the etching process.

The invention will be illustrated by the following set forth examplewhich is being given to set forth the presently known best mode and byway of illustration only and not by way of any limitation. Allparameters such as concentrations, mixing proportions, temperatures,pressure, rates, compounds, etc., submitted in this example are not tobe construed to unduly limit the scope of the invention.

EXAMPLE I

A test semiconductor wafer was formulated with the following film stack:

0.8 μm patterned PR (photoresist)/5000 Å Oxide/100 Å Ti/1000 Å Pt/300 ÅTiN.

The feature size of the patterned PR test semiconductor wafer was 0.3 μmblock and 0.25 μm spacing. The oxide mask (i.e. the mask layer) wasopened in the oxide etch chamber of a plasma processing apparatus soldunder the trademark Oxide Etch MxP Centura™, owned by Applied MaterialsInc., 3050 Bowers Avenue, Santa Clara, Calif. 95054-3299. The etchantgas for opening the oxide mask comprised about 68% by volume Ar andabout 32% by volume CHF₃. The reactor and process conditions were asfollows:

Reactor Conditions Pressure 60 mTorr RF Power 850 watts RotationalMagnetic Field 40 Gauss Temperature of Test Wafer 100° C. Oxide MaskEtch Rate 3000 Å/min

Reactor Conditions Pressure 60 mTorr RF Power 850 watts RotationalMagnetic Field 40 Gauss Temperature of Test Wafer 100° C. Oxide MaskEtch Rate 3000 Å/min

The photoresist was stripped from the oxide mask in an ASP chamber ofthe Metal Etch MxP Centura™ brand plasma processing apparatus under thefollowing recipe using microwave downstream O₂/N₂ plasma: 120 seconds,250° C., 1400 W, 3000 sccm O₂, 300 sccm N₂, and 2 Torr.

The Ti protective layer was etched with Ar, Cl₂ and BCl₃ as the etchantgases and in a DPS™ brand chamber of the Metal Etch DPS Centura™ brandplasma processing apparatus under the following reactor and processconditions:

Reactor Conditions Pressure 12 mTorr RF Power to Coil Inductor 900 wattsRF Power to Wafer Pedestal 100 watts Temperature of Test Wafer 110° C.Ti Etch Rate 2000 Å/min

Reactor Conditions Pressure 12 mTorr RF Power to Coil Inductor 900 wattsRF Power to Wafer Pedestal 100 watts Temperature of Test Wafer 110° C.Ti Etch Rate 2000 Å/min

The platinum layer of the test semiconductor wafer was then etched withAr and Cl₂ as the etchant gas and in a DPS™ brand chamber of the MetalEtch DPS Centura™ brand plasma processing apparatus under the followingreactor and process conditions:

Reactor Conditions Pressure 12 mTorr RF Power to Coil Inductor 900 wattsRF Power to Wafer Pedestal 150 watts Temperature of Test Wafer 260° C.Platinum Etch Rate 1500 Å/min

Reactor Conditions Pressure 12 mTorr RF Power to Coil Inductor 900 wattsRF Power to Wafer Pedestal 150 watts Temperature of Test Wafer 260° C.Platinum Etch Rate 1500 Å/min

The resulting etched platinum layer of the test semiconductor wafer isshown in FIG. 19 wherein a platinum profile of about 87 degrees isshown.

The oxide mask was then removed in a 6:1 HF solution to produce theveil-less test semiconductor wafer shown in FIG. 20. The remaining Tiprotective layer could be removed by any suitable means and/or in anysuitable manner, such as by etching with Ar, BCl₃ and Cl₂ as the etchantgases and in a DPS™ brand chamber of the Metal Etch DPS Centura™ brandplasma processing apparatus under the following reactor and processconditions:

Reactor Conditions Pressure 12 mTorr RF Power to Coil Inductor 900 wattsRF Power to Wafer Pedestal 100 watts Temperature of Test Wafer 110° C.Ti Etch Rate 2000 Å/min

Reactor Conditions Pressure 12 mTorr RF Power to Coil Inductor 900 wattsRF Power to Wafer Pedestal 100 watts Temperature of Test Wafer 110° C.Ti Etch Rate 2000 Å/min

EXAMPLE II

A test semiconductor wafer was formulated with the following film stack:

0.8 μm patterned PR (photoresist)/5000 Å Oxide/600 Å TiN/2000 Å Pt/300 ÅTiN

The feature size of the patterned PR test semiconductor wafer was 0.25μm block and 0.2 μm spacing. The oxide mask (i.e. the mask layer) wasopened in the oxide etch chamber of a plasma processing apparatus soldunder the trademark Oxide Etch MxP Centura™, owned by Applied MaterialsInc., 3050 Bowers Avenue, Santa Clara, Calif. 95054-3299. The etchantgas for opening the oxide mask comprised about 68% by volume Ar andabout 32% by volume CHF₃. The reactor and process conditions were asfollows:

Reactor Conditions Pressure 60 mTorr RF Power 850 watts RotationalMagnetic Field 40 Gauss Temperature of Test Wafer 100° C. Oxide MaskEtch Rate 3000 Å/min

Reactor Conditions Pressure 60 mTorr RF Power 850 watts RotationalMagnetic Field 40 Gauss Temperature of Test Wafer 100° C. Oxide MaskEtch Rate 3000 Å/min

The photoresist was stripped from the oxide mask in an ASP chamber ofthe Metal Etch MxP Centura™ brand plasma processing apparatus under thefollowing recipe using microwave downstream O₂/N₂ plasma: 120 seconds,250° C., 1400 W, 3000 sccm O₂, 300 sccm N₂, and 2 Torr.

The TiN protective layer was etched with Ar, Cl₂ and BCl₃ as the etchantgases and in a DPS™ brand chamber of the Metal Etch DPS Centura™ brandplasma processing apparatus under the following reactor and processconditions:

Reactor Conditions Pressure 12 mTorr RF Power to Coil Inductor 900 wattsRF Power to Wafer Pedestal 100 watts Temperature of Test Wafer 110° C.TiN Etch Rate 2000 Å/min

Reactor Conditions Pressure 12 mTorr RF Power to Coil Inductor 900 wattsRF Power to Wafer Pedestal 100 watts Temperature of Test Wafer 110° C.TiN Etch Rate 2000 Å/min

The platinum layer of the test semiconductor wafer was then etched withAr and Cl₂ and BCl₃ as the etchant gas and in a DPS™ brand chamber ofthe Metal Etch DPS Centura™ brand plasma processing apparatus under thefollowing reactor and process conditions:

Reactor Conditions Pressure 12 mTorr RF Power to Coil Inductor 900 wattsRF Power to Wafer Pedestal 150 watts Temperature of Test Wafer 260° C.Platinum Etch Rate 1500 Å/min

Reactor Conditions Pressure 12 mTorr RF Power to Coil Inductor 900 wattsRF Power to Wafer Pedestal 150 watts Temperature of Test Wafer 260° C.Platinum Etch Rate 1500 Å/min

The resulting etched platinum layer of the test semiconductor wafer isshown in FIG. 23 wherein a platinum profile of about 87 degrees isshown. FIG. 24 is a drawing representing the elevational view in thepicture of FIG. 23 with the respective parts identified by a referencenumeral.

The oxide mask could have been removed in a 6:1 HF solution to produce aveil-less test semiconductor wafer similar to the one shown in FIG. 20.The remaining TiN protective layer could have been removed by anysuitable means and/or in any suitable manner, such as by etching withAr, BCl₃ and Cl₂ as the etchant gases and in a DPS™ brand chamber of theMetal Etch DPS Centura™ brand plasma processing apparatus under thefollowing reactor and process conditions:

Reactor Conditions Pressure 12 mTorr RF Power to Coil Inductor 900 wattsRF Power to Wafer Pedestal 100 watts Temperature of Test Wafer 110° C.TiN Etch Rate 2000 Å/min

Reactor Conditions Pressure 12 mTorr RF Power to Coil Inductor 900 wattsRF Power to Wafer Pedestal 100 watts Temperature of Test Wafer 110° C.TiN Etch Rate 2000 Å/min

EXAMPLE III

A test semiconductor wafer was formulated with the following film stack:

1.2 μm patterned PR (photoresist)/4000 Å Oxide/100Å Ti/2000 Å Ir/1000 ÅTiN

The feature size of the patterned PR test semiconductor wafer was 2.5 μmblock and 4.0 μm spacing. The oxide mask (i.e. the mask layer) wasopened in the oxide etch chamber of a plasma processing apparatus soldunder the trademark Oxide Etch MxP Centura™, owned by Applied MaterialsInc., 3050 Bowers Avenue, Santa Clara, Calif. 95054-3299. The etchantgas for opening the oxide mask comprised about 68% by volume Ar andabout 32% by volume CHF₃. The reactor and process conditions were asfollows:

Reactor Conditions Pressure 60 mTorr RF Power 850 watts RotationalMagnetic Field 40 Gauss Temperature of Test Wafer 100° C. Oxide MaskEtch Rate 3000 Å/min

Reactor Conditions Pressure 60 mTorr RF Power 850 watts RotationalMagnetic Field 40 Gauss Temperature of Test Wafer 100° C. Oxide MaskEtch Rate 3000 Å/min

The photoresist was stripped from the oxide mask in an ASP chamber ofthe Metal Etch MxP Centura™ brand plasma processing apparatus under thefollowing recipe using microwave downstream O₂/N₂ plasma: 120 seconds,250° C., 1400 W, 3000 sccm O₂, 300 sccm N₂, and 2 Torr.

The Ti protective layer was etched with Ar, Cl₂ and BCl₃ as the etchantgases and in a DPS™ brand chamber of the Metal Etch DPS Centura™ brandplasma processing apparatus under the following reactor and processconditions:

Reactor Conditions Pressure 12 mTorr RF Power to Coil Inductor 900 wattsRF Power to Wafer Pedestal 100 watts Temperature of Test Wafer 110° C.Ti Etch Rate 2000 Å/min

Reactor Conditions Pressure 12 mTorr RF Power to Coil Inductor 900 wattsRF Power to Wafer Pedestal 100 watts Temperature of Test Wafer 110° C.Ti Etch Rate 2000 Å/min

The iridium layer of the test semiconductor wafer was then etched withO₂, Ar and Cl₂ as the etchant gas and in a DPS™ brand chamber of theMetal Etch DPS Centura™ brand plasma processing apparatus under thefollowing reactor and process conditions:

Reactor Conditions Pressure 12 mTorr RF Power to Coil Inductor 900 wattsRF Power to Wafer Pedestal 450 watts Temperature of Test Wafer 300° C.Iridium (Ir) Etch Rate 600 Å/min

Reactor Conditions Pressure 12 mTorr RF Power to Coil Inductor 900 wattsRF Power to Wafer Pedestal 450 watts Temperature of Test Wafer 300° C.Iridium (Ir) Etch Rate 600 Å/min

The resulting etched iridium layer of the test semiconductor wafer isshown in the picture of FIG. 25 wherein an iridium profile of about 85degrees is shown. FIG. 26 is a drawing representing the elevational viewin the picture of FIG. 25 with the respective parts identified by areference numeral.

The oxide mask was then removed in a 6:1 HF solution to produce theveil-less test semiconductor wafer. The remaining Ti protective layercould be removed by any suitable means and/or in any suitable manner,such as by etching with Ar, BCl₃ and Cl₂ as the etchant gases and in aDPS™ brand chamber of the Metal Etch DPS Centura™ brand plasmaprocessing apparatus under the following reactor and process conditions:

Reactor Conditions Pressure 12 mTorr RF Power to Coil Inductor 900 wattsRF Power to Wafer Pedestal 100 watts Temperature of Test Wafer 110° C.Ti Etch Rate 2000 Å/min

Reactor Conditions Pressure 12 mTorr RF Power to Coil Inductor 900 wattsRF Power to Wafer Pedestal 100 watts Temperature of Test Wafer 110° C.Ti Etch Rate 2000 Å/min

EXAMPLE IV

A test semiconductor wafer was formulated with the following film stack:

1.2 μm patterned PR (photoresist)/1000 Å TiN/2000 Å Ir/1000 Å TiN

The feature size of the patterned PR test semiconductor wafer was 2.5 μmblock and 4.0 μm spacing. The TiN mask (i.e. the mask layer) was openedin the metal etch chamber of a plasma processing apparatus sold underthe trademark Metal Etch DPS Centura™, owned by Applied Materials Inc.,3050 Bowers Avenue, Santa Clara, Calif. 95054-3299. The etchant gas foropening the TiN mask comprised about 68% by volume Ar and about 32% byvolume Cl₂. The reactor and process conditions were as follows:

Reactor Conditions Pressure 12 mTorr RF Power to Coil Inductor 1200watts RF Power to Wafer Pedestal 100 watts Temperature of Test Wafer110° C. TiN Etch Rate 2000 Å/min

Reactor Conditions Pressure 12 mTorr RF Power to Coil Inductor 1200watts RF Power to Wafer Pedestal 100 watts Temperature of Test Wafer110° C. TiN Etch Rate 2000 Å/min

The photoresist was stripped from the oxide mask in an ASP chamber ofthe Metal Etch MxP Centura™ brand plasma processing apparatus under thefollowing recipe using microwave downstream O₂/N₂ plasma: 120 seconds,250° C., 1400 W, 3000 sccm O₂, 300 sccm N₂, and 2 Torr.

The iridium layer of the test semiconductor wafer was then etched withO₂ Ar and Cl₂ as the etchant gas and in a DPS™ brand chamber of theMetal Etch DPS Centura™ brand plasma processing apparatus under thefollowing reactor and process conditions:

Reactor Conditions Pressure 12 mTorr RF Power to Coil Inductor 900 wattsRF Power to Wafer Pedestal 450 watts Temperature of Test Wafer 320° C.Iridium Etch Rate 600 Å/min

Process Conditions Based on the Flow Rate of O₂ and Ar and Cl₂ O₂ 15sccm Ar 100 sccm Cl₂ 50 sccm Pressure, mTorr 12 mTorr RF Power to CoilInductor 900 watts RF Power to Wafer Pedestal 150 watts Temperature (°C.) of Test Wafer 320° C. Iridium Etch Rate (Å/min) 1500 Å/minSelectivity of Ir/TiN Mask 10:1

The resulting etched iridium layer of the test semiconductor wafer isshown in FIG. 27 wherein an iridium profile of about 80 degrees isshown. FIG. 28 is a drawing representing the elevational view in thepicture of FIG. 27 with the respective parts identified by a referencenumeral.

The remaining TiN mask layer could have been removed by any suitablemeans and/or in any suitable manner, such as by etching with Ar and Cl₂as the etchant gases and in a DPS™ brand chamber of the Metal Etch DPSCentura™ brand plasma processing apparatus under the following reactorand process conditions:

Reactor Conditions Pressure 12 mTorr RF Power to Coil Inductor 1200watts RF Power to Wafer Pedestal 100 watts Temperature of Test Wafer110° C. TiN Etch Rate 2000 Å/min

Reactor Conditions Pressure 12 mTorr RF Power to Coil Inductor 1200watts RF Power to Wafer Pedestal 100 watts Temperature of Test Wafer110° C. TiN Etch Rate 2000 Å/min

CONCLUSION

Thus, by the practice of the present invention there is provided amethod for etching of the electrode layer 16. The etched electrode layer16 includes a plurality of etched electrode layers 16 a, 16 b, 16 c and16 d having a profile where the angle α of the sidewalls 16 s withrespect to a horizontal plane is equal to or greater than about 80degrees. The electrode layers 16 a, 16 b, 16 c and 16 d are separated bya distance or space having a dimension equal to or less than about 0.3μm. Each of the electrode layers 16 a, 16 b, 16 c and 16 d include adimension having a value equal to or less than about 0.6 μm, preferablyequal to or less than about 0.3 μm. More preferably, each of theelectrode layers 16 a, 16 b, 16 c and 16 d has a width equal to or lessthan about 0.3 μm, a length equal to or less than about 0.6 μm, and aheight equal to or less than about 0.6 μm. Because the produced etchedelectrode layers 16 a, 16 b, 16 c and 16 d are essentially a “veil-less”with no “fences” or “rabbit ears,” they are ideally suited for receivinga dielectric (e.g., a BST layer) in producing a semiconductor device.The etchant gas in Example I consisted of about 40% by vol. Ar and about60% by vol. Cl₂, and produced an etched platinum layer with a platinumprofile of about 87 degrees. In Example II, the etchant gas consisted of54.5% by vol. (about 55% by vol.) Cl₂, 36.4% by vol. (about 36% by vol.)Ar, and 9.1% by vol. (about 9% by vol.) BCl₃, and the resulting etchedplatinum layer had a platinum profile of about 87 degrees. In ExampleIII, the etchant gas consisted of about 9.1% by vol. O₂, about 60.6% byvol. argon, and about 30.3% by vol. Cl₂, and produced an etched iridiumlayer with an iridium profile of about 85 degrees. In Example IV, theetchant gas consisted of about 9.1% by vol. O₂, about 60.6% by vol.argon, and about 30.3% by vol. Cl₂, and produced an etched iridium layerwith an iridium profile of about 80 degrees.

Thus, while the present invention has been described herein withreference to particular embodiments thereof, a latitude of modification,various changes and substitutions are intended in the foregoingdisclosure, and it will be appreciated that in some instances somefeatures of the invention will be employed without a corresponding useof other features without departing from the scope and spirit of theinvention as set forth. Therefore, many modifications may be made toadapt a particular situation or material to the teachings of theinvention without departing from the essential scope and spirit of thepresent invention. It is intended that the invention not be limited tothe particular embodiment(s) disclosed as the best mode contemplated forcarrying out this invention, but that the invention will include allembodiments and equivalents falling within the scope of the appendedclaims.

What is claimed is:
 1. A method of etching an iridium layer disposed ona substrate comprising the steps of: a) providing a substrate supportingan iridium layer; b) heating said substrate of step (a) to a temperaturegreater than about 150° C.; and c) etching said iridium layer includingemploying a high density plasma of an etchant gas comprising a halogencontaining gas and a noble gas to produce said substrate supporting atleast one etched iridium layer.
 2. The method of claim 1 wherein saidetchant gas additionally comprises a gas selected from the groupconsisting of O₂ and BCl₃.
 3. The method of claim 1 wherein said etchantgas additionally comprises a gas selected from the group consisting ofO₂, HCl, HBr, and mixtures thereof.
 4. The method of claim 1 whereinsaid etched iridium layer includes an iridium profile equal to orgreater than about 80°.
 5. The method of claim 1 wherein said halogencontaining gas consists essentially of chlorine and said noble gasconsists essentially of argon.
 6. The method of claim 5 wherein saidetchant gas consists essentially of chlorine, argon and O₂.
 7. Themethod of claim 1 wherein said iridium layer of step (a) additionallycomprises a mask layer disposed on a selected part of said iridium layerto selectively protect said iridium layer during said etching step (c).8. The method of claim 1 wherein said iridium layer of step (a)additionally comprises a TiN mask layer disposed on a selected part ofsaid iridium layer to selectively protect said iridium layer during saidetching step (c).
 9. The method of claim 1 wherein said iridium layer ofstep (a) additionally comprises a Ti mask layer disposed on a selectedpart of said iridium layer to selectively protect said iridium layerduring said etching step (c).
 10. The method of claim 7 wherein saidiridium layer of step (a) additionally comprises a protective layerdisposed on said selected part of said iridium layer between said masklayer and said iridium layer.
 11. The method of claim 8 wherein saidiridium layer of step (a) additionally comprises a protective layerdisposed on said selected part of said iridium layer between said TiNmask layer and said iridium layer.
 12. The method of claim 9 whereinsaid iridium layer of step (a) additionally comprises a protective layerdisposed on said selected part of said iridium layer between said Timask layer and said iridium layer.
 13. The method of claim 7additionally comprising removing said mask layer after said etching step(c).
 14. The method of claim 1 wherein said high density plasma includesa high density inductively coupled plasma.
 15. The method of claim 14additionally comprising disposing said substrate including said iridiumlayer of step (a) in a high density plasma chamber including a coilinductor and a wafer pedestal; and performing said etching step (c) insaid high density plasma chamber under the following process conditions:Process Parameters Etchant Gas flow 50 to 500 sccm Pressure, mTorr 0.1to 300 milliTorr RF Power (watts) 100 to 5000 watts of Coil Inductor RFPower (watts) 50 to 3000 watts of Wafer Pedestal Iridium Etch Rate(Å/min) 200 to 6000 Å/min RF Frequency of 100K to 300 MHz Coil InductorRF Frequency of 100K to 300 MHz Wafer Pedestal.


16. The method of claim 8 wherein said high density plasma includes ahigh density inductively coupled plasma, and said etchant gasadditionally comprises O₂.
 17. The method of claim 16 additionallycomprising disposing said substrate including said iridium layer of step(a) in a high density plasma chamber including a coil inductor and awafer pedestal; and performing said etching step (c) in said highdensity plasma chamber under the following process conditions: ProcessParameters O₂ 5% to 40% by vol. Cl₂ 10% to 60% by vol. Ar 30% to 80% byvol. Pressure, mTorr 0.1 to 300 milliTorr RF Power (watts) 100 to 5000watts of Coil Inductor RF Power (watts) 50 to 3000 watts of WaferPedestal Iridium Etch Rate (Å/min) 200 to 6000 Å/min Selectivity of Irto TiN .2 to 50 RF Frequency of 100K to 300 MHz Coil Inductor RFFrequency of 100K to 300 MHz Wafer Pedestal.


18. A method for producing a capacitance structure including an iridiumelectrode comprising the steps of: a) providing a substrate supportingan iridium electrode layer and at least one mask layer disposed on aselected part of said iridium electrode layer; b) heating said substrateof step (a) to a temperature greater than about 150° C.; and c) etchingsaid iridium electrode layer including employing a plasma of an etchantgas comprising a halogen containing gas and a noble gas to produce acapacitance structure having at least one iridium electrode.
 19. Acapacitance structure produced in accordance with the method of claim18.
 20. A method of manufacturing a semiconductor device comprising thesteps of: a) forming a patterned resist layer, a TiN mask layer and aniridium electrode layer on a substrate having circuit elements formedthereon; b) etching a portion of said TiN mask layer including employinga plasma of an etchant gas to break through and to remove said portionof said TiN mask layer from said iridium electrode layer to produce saidsubstrate supporting said patterned resist layer, a residual TiN masklayer, and said iridium electrode layer; c) removing said patternedresist layer of step (b) to produce said substrate supporting saidresidual TiN mask layer and said iridium electrode layer; d) heatingsaid substrate of step (c) to a temperature greater than about 150° C.;and e) etching said iridium electrode layer of step (d) includingemploying a high density plasma of an etchant gas comprising a halogencontaining gas and a noble gas to produce a semiconductor device havingat least one iridium electrode.
 21. The method of claim 20 additionallycomprising removing said residual TiN mask layer after said etching step(e).
 22. The method of claim 20 wherein said etchant gas of said highdensity plasma of step (e) consists essentially of oxygen, chlorine andargon.
 23. A method of etching an iridium electrode layer disposed on asubstrate comprising the steps of: a) providing a substrate supportingan iridium electrode layer, a protective layer on said iridium electrodelayer, a Ti mask layer on said protective layer, and a patterned resistlayer on said mask layer; b) etching a portion of said Ti mask layerincluding employing a plasma of an etchant gas to break through and toremove said portion of said Ti mask layer from said iridium electrodelayer to expose part of said protective layer and to produce saidsubstrate supporting said iridium electrode layer, said protective layeron said iridium electrode layer, a residual Ti mask layer on saidprotective layer, and said patterned resist layer on said residual Timask layer; c) removing said patterned resist layer from said residualTi mask layer of step (b) to produce said substrate supporting saidiridium electrode layer, said protective layer on said iridium electrodelayer, and said residual mask layer on said protective layer; d) heatingsaid substrate of step (c) to a temperature greater than about 150° C.;e) etching said exposed part of said protective layer to expose part ofsaid iridium electrode layer and to produce said substrate supportingsaid iridium electrode layer, a residual protective layer on saidiridium electrode layer, and said residual mask layer on said residualprotective layer; and f) etching said exposed part of said iridiumelectrode layer of step (e) including employing a high density plasma ofan etchant gas comprising a halogen containing gas and a noble gas toproduce said substrate supporting an etched iridium electrode layerhaving said residual protective layer on said etched iridium electrodelayer, and said residual Ti mask layer on said residual protectivelayer.
 24. A method of etching an iridium electrode layer disposed on asubstrate comprising the steps of: a) providing a substrate supportingan iridium electrode layer, a protective layer on said iridium electrodelayer, a mask layer on said protective layer, and a patterned resistlayer on said mask layer; b) etching a portion of said mask layerincluding employing a plasma of an etchant gas to break through and toremove said portion of said mask layer from said iridium electrode layerto expose part of said protective layer and to produce said substratesupporting said iridium electrode layer, said protective layer on saidiridium electrode layer, a residual mask layer on said protective layer,and said patterned resist layer on said residual mask layer; c) etchingsaid exposed part of said protective layer to expose part of saidiridium electrode layer and to produce said substrate supporting saidiridium electrode layer, a residual protective layer on said iridiumelectrode layer, said residual mask layer on said residual protectivelayer, and said patterned resist layer on said residual mask layer; d)removing said patterned resist layer from said residual mask layer ofstep (c) to produce said substrate supporting said iridium electrodelayer, said residual protective layer on said iridium electrode layer,and said residual mask layer on said residual protective layer; e)heating said substrate of step (d) to a temperature greater than about150° C.; and f) etching said exposed part of said iridium electrodelayer of step (d) including employing a high density plasma of anetchant gas comprising chlorine and a noble gas to produce saidsubstrate supporting an etched iridium electrode layer having saidresidual protective layer on said etched iridium electrode layer, andsaid residual mask layer on said residual protective layer.
 25. Themethod of claim 24 wherein said etchant gas of step (f) additionallycomprises a gas selected from the group consisting of oxygen, HCl, HBrand mixtures thereof.
 26. The method of claim 1 wherein said halogencontaining gas is a halogen gas and said etchant gas comprises fromabout 20% by volume to about 95% by volume of the halogen gas and fromabout 5% by volume to about 80% by volume of the noble gas.
 27. Themethod of claim 1 wherein said halogen containing gas is a halogen gasand said etchant gas comprises from about 40% by volume to about 80% byvolume of the halogen gas and from about 20% by volume to about 60% byvolume of the noble gas.
 28. The method of claim 1 wherein said halogencontaining gas is a halogen gas and said etchant gas comprises fromabout 55% by volume to about 65% by volume of the halogen gas and fromabout 35% by volume to about 45% by volume of the noble gas.
 29. Themethod of claim 2 wherein said halogen containing gas is a halogen gasand said etchant gas comprises from about 5% by volume to about 40% byvolume oxygen, from about 10% by volume to about 60% by volume of thehalogen gas, and from about 30% by volume to about 80% by volume of thenoble gas.
 30. The method of claim 2 wherein said halogen containing gasis a halogen gas and said etchant gas comprises from about 10% by volumeto about 30% by volume oxygen, from about 20% by volume to about 50% byvolume of the halogen gas, and from about 40% by volume to about 70% byvolume of the noble gas.
 31. The method of claim 2 wherein said halogencontaining gas is a halogen gas and said etchant gas comprises fromabout 10% by volume to about 20% by volume oxygen, from about 20% byvolume to about 30% by volume of the halogen gas, and from about 50% byvolume to about 70% by volume of the noble gas.
 32. The method of claim3 wherein said halogen containing gas is a halogen gas and said etchantgas comprises from about 10% by volume to about 90% by volume of thehalogen gas, from about 5% by volume to about 80% by volume of the noblegas, and from about 4% by volume to about 25% by volume of a gasselected from the group consisting of HBr, BCl₃, and mixtures thereof.33. The method of claim 3 wherein said halogen containing gas is ahalogen gas and said etchant gas comprises from about 40% by volume toabout 70% by volume of the halogen gas, from about 25% by volume toabout 55% by volume of the noble gas, and from about 5% by volume toabout 20% by volume of gas selected from the group consisting of HBr,BCl₃, and mixtures thereof.
 34. The method of claim 3 wherein saidhalogen containing gas is a halogen gas and said etchant gas comprisesfrom about 50% by volume to about 60% by volume of the halogen gas, fromabout 35% by volume to about 45% by volume of the noble gas, and fromabout 5% by volume to about 15% by volume of gas selected from the groupconsisting of HBr, BCl₃, and mixtures thereof.
 35. The method of claim 3wherein said halogen containing gas is a halogen gas and said etchantgas comprises from about 5% by volume to about 20% by volume oxygen,from about 10% by volume to about 60% by volume of the halogen gas, fromabout 30% by volume of about 80% by volume of the noble gas, and fromabout 5% by volume to about 20% by volume of a gas selected from thegroup consisting of HBr, HCl, and mixtures thereof.
 36. The method ofclaim 3 wherein said halogen containing gas is a halogen gas and saidetchant gas comprises from about 5% by volume to about 15% by volumeoxygen, from about 20% by volume to about 50% by volume of the halogengas, from about 40% by volume of about 70% by volume of the noble gas,and from about 5% by volume to about 15% by volume of a gas selectedfrom the group consisting of HBr, HCl, and mixtures thereof.
 37. Themethod of claim 3 wherein said halogen containing gas is a halogen gasand said etchant gas comprises from about 5% by volume to about 10% byvolume oxygen, from about 20% by volume to about 35% by volume of thehalogen gas, from about 40% by volume of about 60% by volume of thenoble gas, and from about 5% by volume to about 10% by volume of a gasselected from the group consisting of HBr, HCl, and mixtures thereof.38. The method of claim 1 wherein said temperature of said substrateranges from about 200° C. to about 400° C.
 39. The method of claim 1wherein said temperature of said substrate ranges from about 250° C. toabout 350° C.
 40. The method of claim 18 wherein said etchant gasadditionally comprises a gas selected from the group consisting of O₂and BCl₃.
 41. The method of claim 18 wherein said etchant gasadditionally comprises a gas selected from the group consisting of O₂,HCl, HBr, and mixtures thereof.
 42. The method of claim 18 wherein saidetched iridium electrode layer includes an iridium profile equal to orgreater than about 80°.
 43. The method of claim 18 wherein said halogencontaining gas consists essentially of chlorine and said noble gasconsists essentially of argon.
 44. The method of claim 43 wherein saidetchant gas consists essentially of chlorine, argon and O₂.
 45. Themethod of claim 18 wherein said mask layer comprises a TiN mask layerdisposed on a selected part of said iridium electrode layer toselectively protect said iridium electrode layer during said etchingstep (c).
 46. The method of claim 18 wherein said mask layer comprises amask layer including Ti and TiN disposed on a selected part of saidiridium electrode layer to selectively protect said iridium electrodelayer during said etching. step (c).
 47. The method of claim 18 whereinsaid mask layer comprises a Ti mask layer disposed on a selected part ofsaid iridium electrode layer to selectively protect said iridiumelectrode layer during said etching step (c).
 48. The method of claim 45wherein said iridium electrode layer of step (a) additionally comprisesa protective layer disposed on said selected part of said iridiumelectrode layer between said TiN mask layer and said iridium electrodelayer.
 49. The method of claim 46 wherein said iridium electrode layerof step (a) additionally comprises a protective layer disposed on saidselected part of said iridium electrode layer between said mask layerand said iridium electrode layer.
 50. The method of claim 47 whereinsaid iridium electrode layer of step (a) additionally comprises aprotective layer disposed on said selected part of said iridiumelectrode layer between said Ti mask layer and said iridium electrodelayer.
 51. The method of claim 45 additionally comprising removing saidmask layer after said etching step (c).
 52. The method of claim 18wherein said high density plasma includes a high density inductivelycoupled plasma.
 53. The method of claim 52 additionally comprisingdisposing said substrate including said iridium electrode layer of step(a) in a high density plasma chamber including a coil inductor and awafer pedestal; and performing said etching step (c) in said highdensity plasma chamber under the following process conditions: ProcessParameters Etchant Gas flow 50 to 500 sccm Pressure, mTorr 0.1 to 300milliTorr RF Power (watts) 100 to 5000 watts of Coil Inductor RF Power(watts) 50 to 3000 watts of Wafer Pedestal Iridium Etch Rate (Å/min) 200to 6000 Å/min RF Frequency of 100K to 300 MHz Coil Inductor RF Frequencyof 100K to 300 MHz Wafer Pedestal.


54. The method of claim 45 wherein said high density plasma includes ahigh density inductively coupled plasma, and said etchant gasadditionally comprises O₂.
 55. The method of claim 54 additionallycomprising disposing said substrate including said iridium electrodelayer of step (a) in a high density plasma chamber including a coilinductor and a wafer pedestal; and performing said etching step (c) insaid high density plasma chamber under the following process conditions:Process Parameters O₂ 5% to 40% by vol. Cl₂ 10% to 60% by vol. Ar 30% to80% by vol. Pressure, mTorr 0.1 to 300 milliTorr RF Power (watts) 100 to5000 watts of Coil Inductor RF Power (watts) 50 to 3000 watts of WaferPedestal Iridium Etch Rate (Å/min) 200 to 6000 Å/min Selectivity of Irto TiN .2 to 50 RF Frequency of 100K to 300 MHz Coil Inductor RFFrequency of 100K to 300 MHz Wafer Pedestal.


56. The method of claim 18 wherein said halogen containing gas is ahalogen gas and said etchant gas comprises from about 20% by volume toabout 95% by volume of the halogen gas and from about 5% by volume toabout 80% by volume of the noble gas.
 57. The method of claim 18 whereinsaid halogen containing gas is a halogen gas and said etchant gascomprises from about 40% by volume to about 80% by volume of the halogengas and from about 20% by volume to about 60% by volume of the noblegas.
 58. The method of claim 18 wherein said halogen containing gas is ahalogen gas and said etchant gas comprises from about 55% by volume toabout 65% by volume of the halogen gas and from about 35% by volume toabout 45% by volume of the noble gas.
 59. The method of claim 40 whereinsaid halogen containing gas is a halogen gas and said etchant gascomprises from about 5% by volume to about 40% by volume oxygen, fromabout 10% by volume to about 60% by volume of the halogen gas, and fromabout 30% by volume to about 80% by volume of the noble gas.
 60. Themethod of claim 40 wherein said halogen containing gas is a halogen gasand said etchant gas comprises from about 10% by volume to about 30% byvolume oxygen, from about 20% by volume to about 50% by volume of thehalogen gas, and from about 40% by volume to about 70% by volume of thenoble gas.
 61. The method of claim 40 wherein said halogen containinggas is a halogen gas and said etchant gas comprises from about 10% byvolume to about 20% by volume oxygen, from about 20% by volume to about30% by volume of the halogen gas, and from about 50% by volume to about70% by volume of the noble gas.
 62. The method of claim 41 wherein saidhalogen containing gas is a halogen gas and said etchant gas comprisesfrom about 10% by volume to about 90% by volume of the halogen gas, fromabout 5% by volume to about 80% by volume of the noble gas, and fromabout 4% by volume to about 25% by volume of a gas selected from thegroup consisting of HBr, BCl₃, and mixtures thereof.
 63. The method ofclaim 41 wherein said halogen containing gas is a halogen gas and saidetchant gas comprises from about 40% by volume to about 70% by volume ofthe halogen gas, from about 25% by volume to about 55% by volume of thenoble gas, and from about 5% by volume to about 20% by volume of gasselected from the group consisting of HBr, BCl₃, and mixtures thereof.64. The method of claim 41 wherein said halogen containing gas is ahalogen gas and said etchant gas comprises from about 50% by volume toabout 60% by volume of the halogen gas, from about 35% by volume toabout 45% by volume of the noble gas, and from about 5% by volume toabout 15% by volume of gas selected from the group consisting of HBr,BCl₃, and mixtures thereof.
 65. The method of claim 41 wherein saidhalogen containing gas is a halogen gas and said etchant gas comprisesfrom about 5% by volume to about 20% by volume oxygen, from about 10% byvolume to about 60% by volume of the halogen gas, from about 30% byvolume of about 80% by volume of the noble gas, and from about 5% byvolume to about 20% by volume of a gas selected from the groupconsisting of HBr, HCl, and mixtures thereof.
 66. The method of claim 41wherein said halogen containing gas is a halogen gas and said etchantgas comprises from about 5% by volume to about 15% by volume oxygen,from about 20% by volume to about 50% by volume of the halogen gas, fromabout 40% by volume of about 70% by volume of the noble gas, and fromabout 5% by volume to about 15% by volume of a gas selected from thegroup consisting of HBr, HCl, and mixtures thereof.
 67. The method ofclaim 41 wherein said halogen containing gas is a halogen gas and saidetchant gas comprises from about 5% by volume to about 10% by volumeoxygen, from about 20% by volume to about 35% by volume of the halogengas, from about 40% by volume of about 60% by volume of the noble gas,and from about 5% by volume to about 10% by volume of a gas selectedfrom the group consisting of HBr, HCl, and mixtures thereof.
 68. Themethod of claim 18 wherein said temperature of said substrate rangesfrom about 200° C. to about 400° C.
 69. The method of claim 18 whereinsaid temperature of said substrate ranges from about 250° C. to about350° C.
 70. The method of claim 20 wherein said etchant gas additionallycomprises a gas selected from the group consisting of O₂ and BCl₃. 71.The method of claim 20 wherein said etchant gas additionally comprises agas selected from the group consisting of O₂, HCl, HBr, and mixturesthereof.
 72. The method of claim 20 wherein said etched iridiumelectrode layer includes an iridium profile equal to or greater thanabout 80°.
 73. The method of claim 20 wherein said halogen containinggas consists essentially of chlorine and said noble gas consistsessentially of argon.
 74. The method of claim 73 wherein said etchantgas consists essentially of chlorine, argon and O₂.
 75. The method ofclaim 20 wherein said iridium electrode layer of step (a) additionallycomprises a protective layer disposed on said selected part of saidiridium electrode layer between said mask layer and said iridiumelectrode layer.
 76. The method of claim 20 additionally comprisingremoving said TiN mask layer after said etching step (c).
 77. The methodof claim 20 wherein said high density plasma includes a high densityinductively coupled plasma.
 78. The method of claim 77 additionallycomprising disposing said substrate including said iridium electrodelayer of step (a) in a high density plasma chamber including a coilinductor and a wafer pedestal; and performing said etching step (e) insaid high density plasma chamber under the following process conditions:Process Parameters Etchant Gas flow 50 to 500 sccm Pressure, mTorr 0.1to 300 milliTorr RF Power (watts) 100 to 5000 watts of Coil Inductor RFPower (watts) 50 to 3000 watts of Wafer Pedestal Iridium Etch Rate(Å/min) 200 to 6000 Å/min RF Frequency of 100K to 300 MHz Coil InductorRF Frequency of 100K to 300 MHz Wafer Pedestal.


79. The method of claim 77 wherein said etchant gas additionallycomprises O₂.
 80. The method of claim 79 additionally comprisingdisposing said substrate including said iridium electrode layer of step(a) in a high density plasma chamber including a coil inductor and awafer pedestal; and performing said etching step (e) in said highdensity plasma chamber under the following process conditions: ProcessParameters O₂ 5% to 40% by vol. Cl₂ 10% to 60% by vol. Ar 30% to 80% byvol. Pressure, mTorr 0.1 to 300 milliTorr RF Power (watts) 100 to 5000watts of Coil Inductor RF Power (watts) 50 to 3000 watts of WaferPedestal Iridium Etch Rate (Å/min) 200 to 6000 Å/min Selectivity of Irto TiN .2 to 50 RF Frequency of 100K to 300 MHz Coil Inductor RFFrequency of 100K to 300 MHz Wafer Pedestal.


81. The method of claim 20 wherein said halogen containing gas is ahalogen gas and said etchant gas comprises from about 20% by volume toabout 95% by volume of the halogen gas and from about 5% by volume toabout 80% by volume of the noble gas.
 82. The method of claim 20 whereinsaid halogen containing gas is a halogen gas and said etchant gascomprises from about 40% by volume to about 80% by volume of the halogengas and from about 20% by volume to about 60% by volume of the noblegas.
 83. The method of claim 20 wherein said halogen containing gas is ahalogen gas and said etchant gas comprises from about 55% by volume toabout 65% by volume of the halogen gas and from about 35% by volume toabout 45% by volume of the noble gas.
 84. The method of claim 70 whereinsaid halogen containing gas is a halogen gas and said etchant gascomprises from about 5% by volume to about 40% by volume oxygen, fromabout 10% by volume to about 60% by volume of the halogen gas, and fromabout 30% by volume to about 80% by volume of the noble gas.
 85. Themethod of claim 70 wherein said halogen containing gas is a halogen gasand said etchant gas comprises from about 10% by volume to about 30% byvolume oxygen, from about 20% by volume to about 50% by volume of thehalogen gas, and from about 40% by volume to about 70% by volume of thenoble gas.
 86. The method of claim 70 wherein said halogen containinggas is a halogen gas and said etchant gas comprises from about 10% byvolume to about 20% by volume oxygen, from about 20% by volume to about30% by volume of the halogen gas, and from about 50% by volume to about70% by volume of the noble gas.
 87. The method of claim 71 wherein saidhalogen containing gas is a halogen gas and said etchant gas comprisesfrom about 10% by volume to about 90% by volume of the halogen gas, fromabout 5% by volume to about 80% by volume of the noble gas, and fromabout 4% by volume to about 25% by volume of a gas selected from thegroup consisting of HBr, BCl₃, and mixtures thereof.
 88. The method ofclaim 71 wherein said halogen containing gas is a halogen gas and saidetchant gas comprises from about 40% by volume to about 70% by volume ofthe halogen gas, from about 25% by volume to about 55% by volume of thenoble gas, and from about 5% by volume to about 20% by volume of gasselected from the group consisting of HBr, BCl₃, and mixtures thereof.89. The method of claim 71 wherein said halogen containing gas is ahalogen gas and said etchant gas comprises from about 50% by volume toabout 60% by volume of the halogen gas, from about 35% by volume toabout 45% by volume of the noble gas, and from about 5% by volume toabout 15% by volume of gas selected from the group consisting of HBr,BCl₃, and mixtures thereof.
 90. The method of claim 71 wherein saidhalogen containing gas is a halogen gas and said etchant gas comprisesfrom about 5% by volume to about 20% by volume oxygen, from about 10% byvolume to about 60% by volume of the halogen gas, from about 30% byvolume of about 80% by volume of the noble gas, and from about 5% byvolume to about 20% by volume of a gas selected from the groupconsisting of HBr, HCl, and mixtures thereof.
 91. The method of claim 71wherein said halogen containing gas is a halogen gas and said etchantgas comprises from about 5% by volume to about 15% by volume oxygen,from about 20% by volume to about 50% by volume of the halogen gas, fromabout 40% by volume of about 70% by volume of the noble gas, and fromabout 5% by volume to about 15% by volume of a gas selected from thegroup consisting of HBr, HCl, and mixtures thereof.
 92. The method ofclaim 71 wherein said halogen containing gas is a halogen gas and saidetchant gas comprises from about 5% by volume to about 10% by volumeoxygen, from about 20% by volume to about 35% by volume of the halogengas, from about 40% by volume of about 60% by volume of the noble gas,and from about 5% by volume to about 10% by volume of a gas selectedfrom the group consisting of HBr, HCl, and mixtures thereof.
 93. Themethod of claim 20 wherein said temperature of said substrate rangesfrom about 200° C. to about 400° C.
 94. The method of claim 20 whereinsaid temperature of said substrate ranges from about 250° C. to about350° C.
 95. The method of claim 23 wherein said etchant gas additionallycomprises a gas selected from the group consisting of O₂ and BCl₃. 96.The method of claim 23 wherein said etchant gas additionally comprises agas selected from the group consisting of O₂, HCl, HBr, and mixturesthereof.
 97. The method of claim 23 wherein said etched iridiumelectrode layer includes an iridium profile equal to or greater thanabout 80°.
 98. The method of claim 23 wherein said halogen containinggas consists essentially of chlorine and said noble gas consistsessentially of argon.
 99. The method of claim 98 wherein said etchantgas consists essentially of chlorine, argon and O₂.
 100. The method ofclaim 23 wherein said high density plasma includes a high densityinductively coupled plasma.
 101. The method of claim 100 additionallycomprising disposing said substrate including said iridium electrodelayer of step (a) in a high density plasma chamber including a coilinductor and a wafer pedestal; and performing said etching step (f) insaid high density plasma chamber under the following process conditions:Process Parameters Etchant Gas flow 50 to 500 sccm Pressure, mTorr 0.1to 300 milliTorr RF Power (watts) 100 to 5000 watts of Coil Inductor RFPower (watts) 50 to 3000 watts of Wafer Pedestal Iridium Etch Rate(Å/min) 200 to 6000 Å/min RF Frequency of 100K to 300 MHz Coil InductorRF Frequency of 100K to 300 MHz Wafer Pedestal.


102. The method of claim 23 wherein said high density plasma includes ahigh density inductively coupled plasma, and said etchant gasadditionally comprises O₂.
 103. The method of claim 102 additionallycomprising disposing said substrate including said iridium electrodelayer of step (a) in a high density plasma chamber including a coilinductor and a wafer pedestal; and performing said etching step (f) insaid high density plasma chamber under the following process conditions:Process Parameters O₂ 5% to 40% by vol. Cl₂ 10% to 60% by vol. Ar 30% to80% by vol. Pressure, mTorr 0.1 to 300 milliTorr RF Power (watts) 100 to5000 watts of Coil Inductor RF Power (watts) 50 to 3000 watts of WaferPedestal Iridium Etch Rate (Å/min) 200 to 6000 Å/min Selectivity of Irto Ti .2 to 50 RF Frequency of 100K to 300 MHz Coil Inductor RFFrequency of 100K to 300 MHz Wafer Pedestal.


104. The method of claim 23 wherein said halogen containing gas is ahalogen gas and said etchant gas comprises from about 20% by volume toabout 95% by volume of the halogen gas and from about 5% by volume toabout 80% by volume of the noble gas.
 105. The method of claim 23wherein said halogen containing gas is a halogen gas and said etchantgas comprises from about 40% by volume to about 80% by volume of thehalogen gas and from about 20% by volume to about 60% by volume of thenoble gas.
 106. The method of claim 23 wherein said halogen containinggas is a halogen gas and said etchant gas comprises from about 55% byvolume to about 65% by volume of the halogen gas and from about 35% byvolume to about 45% by volume of the noble gas.
 107. The method of claim95 wherein said halogen containing gas is a halogen gas and said etchantgas comprises from about 5% by volume to about 40% by volume oxygen,from about 10% by volume to about 60% by volume of the halogen gas, andfrom about 30% by volume to about 80% by volume of the noble gas. 108.The method of claim 95 wherein said halogen containing gas is a halogengas and said etchant gas comprises from about 10% by volume to about 30%by volume oxygen, from about 20% by volume to about 50% by volume of thehalogen gas, and from about 40% by volume to about 70% by volume of thenoble gas.
 109. The method of claim 95 wherein said halogen containinggas is a halogen gas and said etchant gas comprises from about 10% byvolume to about 20% by volume oxygen, from about 20% by volume to about30% by volume of the halogen gas, and from about 50% by volume to about70% by volume of the noble gas.
 110. The method of claim 96 wherein saidhalogen containing gas is a halogen gas and said etchant gas comprisesfrom about 10% by volume to about 90% by volume of the halogen gas, fromabout 5% by volume to about 80% by volume of the noble gas, and fromabout 4% by volume to about 25% by volume of a gas selected from thegroup consisting of HBr, BCl₃, and mixtures thereof.
 111. The method ofclaim 96 wherein said halogen containing gas is a halogen gas and saidetchant gas comprises from about 40% by volume to about 70% by volume ofthe halogen gas, from about 25% by volume to about 55% by volume of thenoble gas, and from about 5% by volume to about 20% by volume of gasselected from the group consisting of HBr, BCl₃, and mixtures thereof.112. The method of claim 96 wherein said halogen containing gas is ahalogen gas and said etchant gas comprises from about 50% by volume toabout 60% by volume of the halogen gas, from about 35% by volume toabout 45% by volume of the noble gas, and from about 5% by volume toabout 15% by volume of gas selected from the group consisting of HBr,BCl₃, and mixtures thereof.
 113. The method of claim 96 wherein saidhalogen containing gas is a halogen gas and said etchant gas comprisesfrom about 5% by volume to about 20% by volume oxygen, from about 10% byvolume to about 60% by volume of the halogen gas, from about 30% byvolume of about 80% by volume of the noble gas, and from about 5% byvolume to about 20% by volume of a gas selected from the groupconsisting of HBr, HCl, and mixtures thereof.
 114. The method of claim96 wherein said halogen containing gas is a halogen gas and said etchantgas comprises from about 5% by volume to about 15% by volume oxygen,from about 20% by volume to about 50% by volume of the halogen gas, fromabout 40% by volume of about 70% by volume of the noble gas, and fromabout 5% by volume to about 15% by volume of a gas selected from thegroup consisting of HBr, HCl, and mixtures thereof.
 115. The method ofclaim 96 wherein said halogen containing gas is a halogen gas and saidetchant gas comprises from about 5% by volume to about 10% by volumeoxygen, from about 20% by volume to about 35% by volume of the halogengas, from about 40% by volume of about 60% by volume of the noble gas,and from about 5% by volume to about 10% by volume of a gas selectedfrom the group consisting of HBr, HCl, and mixtures thereof.
 116. Themethod of claim 23 wherein said temperature of said substrate rangesfrom about 200° C. to about 400° C.
 117. The method of claim 23 whereinsaid temperature of said substrate ranges from about 250° C. to about350° C.
 118. The method of claim 24 wherein said etchant gasadditionally comprises a gas selected from the group consisting of O₂and BCl₃.
 119. The method of claim 24 wherein said etchant gasadditionally comprises a gas selected from the group consisting of O₂,HCl, HBr, and mixtures thereof.
 120. The method of claim 24 wherein saidetched iridium electrode layer includes an iridium profile equal to orgreater than about 80°.
 121. The method of claim 24 wherein said halogencontaining gas consists essentially of chlorine and said noble gasconsists essentially of argon.
 122. The method of claim 121 wherein saidetchant gas consists essentially of chlorine, argon and O₂.
 123. Themethod of claim 24 wherein said high density plasma includes a highdensity inductively coupled plasma.
 124. The method of claim 123additionally comprising disposing said substrate including said iridiumelectrode layer of step (a) in a high density plasma chamber including acoil inductor and a wafer pedestal; and performing said etching step (f)in said high density plasma chamber under the following processconditions: Process Parameters Etchant Gas flow 50 to 500 sccm Pressure,mTorr 0.1 to 300 milliTorr RF Power (watts) 100 to 5000 watts of CoilInductor RF Power (watts) 50 to 3000 watts of Wafer Pedestal IridiumEtch Rate (Å/min) 200 to 6000 Å/min RF Frequency of 100K to 300 MHz CoilInductor RF Frequency of 100K to 300 MHz Wafer Pedestal.


125. The method of claim 24 wherein said etchant gas additionallycomprises O₂.
 126. The method of claim 125 additionally comprisingdisposing said substrate including said iridium electrode layer of step(a) in a high density plasma chamber including a coil inductor and awafer pedestal; and performing said etching step (f) in said highdensity plasma chamber under the following process conditions: ProcessParameters O₂ 5% to 40% by vol. Cl₂ 10% to 60% by vol. Ar 30% to 80% byvol. Pressure, mTorr 0.1 to 300 milliTorr RF Power (watts) 100 to 5000watts of Coil Inductor RF Power (watts) 50 to 3000 watts of WaferPedestal Iridium Etch Rate (Å/min) 200 to 6000 Å/min Selectivity of Irto TiN .2 to 50 RF Frequency of 100K to 300 MHz Coil Inductor RFFrequency of 100K to 300 MHz Wafer Pedestal.


127. The method of claim 24 wherein said halogen containing gas is ahalogen gas and said etchant gas comprises from about 20% by volume toabout 95% by volume of the halogen gas and from about 5% by volume toabout 80% by volume of the noble gas.
 128. The method of claim 24wherein said halogen containing gas is a halogen gas and said etchantgas comprises from about 40% by volume to about 80% by volume of thehalogen gas and from about 20% by volume to about 60% by volume of thenoble gas.
 129. The method of claim 24 wherein said halogen containinggas is a halogen gas and said etchant gas comprises from about 55% byvolume to about 65% by volume of the halogen gas and from about 35% byvolume to about 45% by volume of the noble gas.
 130. The method of claim118 wherein said halogen containing gas is a halogen gas and saidetchant gas comprises from about 5% by volume to about 40% by volumeoxygen, from about 10% by volume to about 60% by volume of the halogengas, and from about 30% by volume to about 80% by volume of the noblegas.
 131. The method of claim 118 wherein said halogen containing gas isa halogen gas and said etchant gas comprises from about 10% by volume toabout 30% by volume oxygen, from about 20% by volume to about 50% byvolume of the halogen gas, and from about 40% by volume to about 70% byvolume of the noble gas.
 132. The method of claim 118 wherein saidhalogen containing gas is a halogen gas and said etchant gas comprisesfrom about 10% by volume to about 20% by volume oxygen, from about 20%by volume to about 30% by volume of the halogen gas, and from about 50%by volume to about 70% by volume of the noble gas.
 133. The method ofclaim 119 wherein said halogen containing gas is a halogen gas and saidetchant gas comprises from about 10% by volume to about 90% by volume ofthe halogen gas, from about 5% by volume to about 80% by volume of thenoble gas, and from about 4% by volume to about 25% by volume of a gasselected from the group consisting of HBr, BCl₃, and mixtures thereof.134. The method of claim 119 wherein said halogen containing gas is ahalogen gas and said etchant gas comprises from about 40% by volume toabout 70% by volume of the halogen gas, from about 25% by volume toabout 55% by volume of the noble gas, and from about 5% by volume toabout 20% by volume of gas selected from the group consisting of HBr,BCl₃, and mixtures thereof.
 135. The method of claim 119 wherein saidhalogen containing gas is a halogen gas and said etchant gas comprisesfrom about 50% by volume to about 60% by volume of the halogen gas, fromabout 35% by volume to about 45% by volume of the noble gas, and fromabout 5% by volume to about 15% by volume of gas selected from the groupconsisting of HBr, BCl₃, and mixtures thereof.
 136. The method of claim119 wherein said halogen containing gas is a halogen gas and saidetchant gas comprises from about 5% by volume to about 20% by volumeoxygen, from about 10% by volume to about 60% by volume of the halogengas, from about 30% by volume of about 80% by volume of the noble gas,and from about 5% by volume to about 20% by volume of a gas selectedfrom the group consisting of HBr, HCl, and mixtures thereof.
 137. Themethod of claim 119 wherein said halogen containing gas is a halogen gasand said etchant gas comprises from about 5% by volume to about 15% byvolume oxygen, from about 20% by volume to about 50% by volume of thehalogen gas, from about 40% by volume of about 70% by volume of thenoble gas, and from about 5% by volume to about 15% by volume of a gasselected from the group consisting of HBr, HCl, and mixtures thereof.138. The method of claim 119 wherein said halogen containing gas is ahalogen gas and said etchant gas comprises from about 5% by volume toabout 10% by volume oxygen, from about 20% by volume to about 35% byvolume of the halogen gas, from about 40% by volume of about 60% byvolume of the noble gas, and from about 5% by volume to about 10% byvolume of a gas selected from the group consisting of HBr, HCl, andmixtures thereof.
 139. The method of claim 24 wherein said temperatureof said substrate ranges from about 200° C. to about 400° C.
 140. Themethod of claim 24 wherein said temperature of said substrate rangesfrom about 250° C. to about 350° C.